Small Arms Ammunition

[Daryk]

I found this on YouTube: https://www.youtube.com/watch?v=BoBOuv6qJNU

Given that the bog standard Auto-Rifle uses ammunition that weighs around what standard 5.56 does now (about half a kilo for 30 rounds), it seems completely reasonable that "modern" ammo would be more powerful than current 5.56.  The polymer casings used in the video are about 30% lighter AND achieve a higher muzzle velocity with a larger bullet (6.8 mm vice 5.56).  If you put that weight savings into MORE power you can easily explain the improvement from the "Vintage Auto-Rifle" damage of 2 AP/3 BD to the current Auto-Rifle's 4/4.  And the improved heat management helps explain the increased burst rate (from 10 to 15) too.

[Daemion]

Nice find.
Since we're on small arms ammo, I have a couple questions which I'm only expecting guesses for:

- Refresher: It takes a 15-round burst for a 4/4 weapon to get up above the .5 damage needed to round up to a full BT point, right?
- How much does the bullet weigh?  I'm assuming equivalent to the 5.56 NATO.
- Does anyone know roughly what the GAU-8's projectiles weigh, once free of the casing and powder (, and sabot if it uses 'em)?

I know where I'm trying to go with this.  I'm hoping some of you can pick up on it.

I'm wanting to discuss the merits of penetration power.  What some people fail to realize is that mass has something to do with it.  I'm trying to figure out a baseline where, currently, the GAU-8 is considered a viable anti-tank/armor weapon, but most small-arms are not.

[CVB]

GAU-8
Armor Piercing Incendiary (API): projectile weight 395 g
High Explosive Incendiary (HEI): projectile weight 378 g

Edit:
The PGU-14/B API  projectile consists of a lightweight aluminum body, cast around a smaller caliber depleted uranium penetrating core, so no sabot.
Additional info for API:
v₀ = 1,000 m/s
Muzzle energy = 200 kJ

[Daryk]

A 15 round burst does in fact get a 4/4 weapon over the 0.5 threshold.

I would expect the bullet to weigh more.  A 5.56 bullet weighs 4 to 4.1 grams.  The 6.8 bullet is probably around 5 grams, maybe 6.

GAU-8 AP rounds weigh about 400 grams (they use depleted Uranium alloy).  There's really no comparison to small arms ammo with them.

[Daemion]

Thanks, guys.  That really helps.

[DevianID]

So imho the battletech autorifle probably uses caseless high explosive low velocity ammo in the 9/10 mm range.  It has a lot (a lot) of stopping power but as a low velocity caseless round you can also rapid fire them and won't break your arm shooting them.  Caseless because the autorifle is tech C so they ironed out the kinks in the 3mm real world caseless we tried but couldn't perfect.

[Daryk]

It certainly could use caseless ammo, but I think TPTB were deliberately vague on that point.

[SlightlyIrritatedCat]

Plus you have in universe sources that specifically point out that some small arms are caseless but not others, and in other parts of the fiction you have weapons leaving expended cases.  Just like IRL nothing says that every small arm in the Sphere will be using the same ammunition.  They're probably a mix of various cased and caseless technologies depending on the manufacturer and the intended role of the small arm.

And given that their armor technology has shifted toward ablative or semi-ablative materials, as well as the shorter engagement ranges.  This could well indicate they prioritize rate of fire over projectile velocity because it's more important for them to be able to lay down a dozen or two rounds into a small group instead of one to three rounds with much higher velocity and energy.

[CVB]

Do we have any canon sources on the legality of explosive small arms ammo in BT universe international warfare? There have been attempts of limitations as least as far back as the 1868 St. Petersburg declarations, and the reasons weren't entirely humanitarian only (not going any deeper because of forum rules).

[Daemion]

While it's interesting to try to wrap your head around, even Sarna points out the inconsistencies of the abstract Infantry rules for the standard scale game.

And, mass does seem to play some part in it. While people complain about slow impacts doing damage, I'd like to point out that a Wasp's punch which does two armor/internal damage weighs in probably around 2 tons, more or less. (That value is derived for the replacement cost for a location's internal structure out of ye olde BMR Repairs and Replacements rules.  I'd also like to point out that replacement myomer is based on engine rating on top of that.) 

Funny how that lines up with how the damage is calculated.

But, to look at the math, that's 2,000 kg.  Or, 2,000,000 grams.  Compared to 400 or 6 grams.

And, we haven't added velocity into the mix yet, but it really should be a factor. I'm not going to go into it, but there it is.

It is nice to see improvements in modern day.  I'm wondering, though, if armor defeating rounds for small arms might actuall include some heavy metal in their projectiles, along with, maybe, some microchipped homing and self propulsion.
 

[DOC_Agren]

It certainly could use caseless ammo, but I think TPTB were deliberately vague on that point.

which I don't mind...
some weapons using caseless, other spray cases everywhere it was the future of the 80's

[idea weenie]

While it's interesting to try to wrap your head around, even Sarna points out the inconsistencies of the abstract Infantry rules for the standard scale game.

And, mass does seem to play some part in it. While people complain about slow impacts doing damage, I'd like to point out that a Wasp's punch which does two armor/internal damage weighs in probably around 2 tons, more or less. (That value is derived for the replacement cost for a location's internal structure out of ye olde BMR Repairs and Replacements rules.  I'd also like to point out that replacement myomer is based on engine rating on top of that.) 

Funny how that lines up with how the damage is calculated.

But, to look at the math, that's 2,000 kg.  Or, 2,000,000 grams.  Compared to 400 or 6 grams.

And, we haven't added velocity into the mix yet, but it really should be a factor. I'm not going to go into it, but there it is.

It is nice to see improvements in modern day.  I'm wondering, though, if armor defeating rounds for small arms might actuall include some heavy metal in their projectiles, along with, maybe, some microchipped homing and self propulsion.
 

One thing I tend to use as a yardstick, is the SRM.  It is 10 kg, delivers 2 pts of BT damage, at a range of 9 hexes.  Simplifying, that is 5 kg for 1 pt of BT damage at 9 hexes.

Balance the other anti-Mech weapons with respect to that, and you have some nice flexibility.

Want more range?  You can't reduce the damage so you have to raise the mass
Want more damage?  Either lower the range or raise the mass.
Want less mass?  Lower the range (damage is already at the minimum)

So if you want something massing a total of 800 grams (projectile weight ~400 grams) to do 1 pt of damage at 9 hexes, then you will need 6-7 of them.  If you want something massing 12 grams (with a 6 gram projectile) to do 1 pt of damage at 9 hexes, then you will need ~400 of them

[RifleMech]

I found this on YouTube: https://www.youtube.com/watch?v=BoBOuv6qJNU

Given that the bog standard Auto-Rifle uses ammunition that weighs around what standard 5.56 does now (about half a kilo for 30 rounds), it seems completely reasonable that "modern" ammo would be more powerful than current 5.56.  The polymer casings used in the video are about 30% lighter AND achieve a higher muzzle velocity with a larger bullet (6.8 mm vice 5.56).  If you put that weight savings into MORE power you can easily explain the improvement from the "Vintage Auto-Rifle" damage of 2 AP/3 BD to the current Auto-Rifle's 4/4.  And the improved heat management helps explain the increased burst rate (from 10 to 15) too.

Very cool but I know I missed somethings. How does the 6.8 plastic round compare to a brass one the same size? How much of the improvement is the larger round and how much the casing when compared to the 5.56? And what's the difference between the Civilian and Military versions?

Also at one point the M240 7.62mm machine gun was quickly refitted to fire the plastic 6.8mm round. How do the two rounds compare? Besides the 6.8mm plastic being lighter so more rounds can be carried. Also would the M240 still be a vintage machine gun with the new barrel and ammo or a new weapon? How do we handle it in came terms?  Quirks?  An easy ammo conversion quirk? Takes x turns to complete? And a complicated conversion quirk must send back to the shop to be done?

Also, how do we handle replica firearms that are manufactured to more modern standards? And from what I read rounds are made to be fired by older weapons. Will that remain true in the future?

[Daryk]

For starters, it's 30% lighter overall compared to the 5.56 cartridge.  It also has a higher muzzle velocity.  With a an extra gram or two of bullet and the higher muzzle velocity, that's a LOT more damage down range.  There was also a mention of some kind of geometry change internal to the cartridge.  Advances in fluid dynamics also impact ballistics... 

[Nicoli]

It is nice to see improvements in modern day.  I'm wondering, though, if armor defeating rounds for small arms might actuall include some heavy metal in their projectiles, along with, maybe, some microchipped homing and self propulsion.
 

Doesn't matter if they do, Armor weakens after each successive hit regardless if it penetrates or not. This is why things like motorcycle helmets should be checked after a drop from a good height. Armor designed to handle stronger impacts either need to be incredibly thick and heavy to resist that weakening, or use self destruction to handle it. Battletech armor is handled very much of the self-sacrificing variety which means it can be degraded by multiple small hits.

[RifleMech]

For starters, it's 30% lighter overall compared to the 5.56 cartridge.  It also has a higher muzzle velocity.  With a an extra gram or two of bullet and the higher muzzle velocity, that's a LOT more damage down range.  There was also a mention of some kind of geometry change internal to the cartridge.  Advances in fluid dynamics also impact ballistics... 

Which means what exactly, beyond the 30% increase in ammo? I think he said the range was increased but the accuracy fell off because of the moving barrel. If I remember right wouldn't they cancel each other out?  I'm also going to guess that there's an increased AP/BD. But would it be +1 to each or +2 to one or the other? Also what about when the barrel gets swapped with the ammo? Would everything be improved?
What about when the ammo gets smaller? Number of rounds goes up the rest stays the same?

[Daryk]

If you invest the 30% weight savings in more bullet and/or propellant, you get more damage down range.  The point I was making was that 4/4 Auto-Rifle ammo weighs the SAME as 5.56 (30 rounds for half a kilo), so if the individual cartridges don't waste mass on brass, it seems obvious that's where the extra 2 AP and 1 BD come from.

And as far as what the guy in the video said, he pointed out that a moving barrel tends to reduce accuracy, but he used that fact to transition to talking about the ammo as a way to overcome that problem (i.e., higher muzzle velocity).

[RifleMech]

If you invest the 30% weight savings in more bullet and/or propellant, you get more damage down range.  The point I was making was that 4/4 Auto-Rifle ammo weighs the SAME as 5.56 (30 rounds for half a kilo), so if the individual cartridges don't waste mass on brass, it seems obvious that's where the extra 2 AP and 1 BD come from.

And as far as what the guy in the video said, he pointed out that a moving barrel tends to reduce accuracy, but he used that fact to transition to talking about the ammo as a way to overcome that problem (i.e., higher muzzle velocity).

The thing is that weapon wasn't firing a 5.56. It was firing a 6.8. If the 6.8 is the Auto-Rifle wouldn't the increased;
AP come from the bigger round fired?
BD come from the auto-rifle's increased rate of fire?
power go to longer range?

What happens when the M270 is refitted from 7.62 to 6.8? Same everything but more ammo?

What happens to the Vintage Auto-Rifle firing a plastic 5.56 round? Will it blow up, have an increase in range, AP and BD, or just have 30% more rounds for the weight?

I've also read that rounds are made to be backwards compatible with older guns. I don't think that would change in the future. I can see new rounds made for new guns but you'd still want to be able to retrofit some weapons at least. Like what they did with the M270.

Let's say they made plastic rounds in .38 caliber. Would the Vintage Revolver blow up, or would the round be made to work with the gun? If made to work with the gun, would everything stay the same, except ammo weight, or would there be any increases in performance?

[Daryk]

The only M270 I'm seeing is the Multiple Launch Rocket System (MLRS).  Do you mean the M240 machine gun?  That was actually featured in the video (and yes, it only took a barrel change to enable firing the plastic cased ammo; in that specific case, it would mean more ammo (a LOT more), and enable longer bursts through reduced heat transferred to the block).

To be clear, I'm NOT saying the Auto-Rifle is 6.8mm.  I'm saying this particular technology leap could easily explain how you get to the Auto-Rifle (4/4) from the "Vintage" Auto-Rifle (2/3).

And as far as the mechanics, AP and BD are separate from the burst rate.  Single shots have the same AP and BD as bursts, and bursts simply increase the damage a particular weapon does at the TW scale (AToW Companion page 171 for that; the mechanic is different at AToW scale: AToW page 179 refers).

[RifleMech]

The only M270 I'm seeing is the Multiple Launch Rocket System (MLRS).  Do you mean the M240 machine gun?  That was actually featured in the video (and yes, it only took a barrel change to enable firing the plastic cased ammo; in that specific case, it would mean more ammo (a LOT more), and enable longer bursts through reduced heat transferred to the block).

Yeah. The M240. Sorry. Don't know where the 7 came from. So with the new barrel and ammo, the BD would go up from increased rate of fire. What about the AP and range? Would they go down or would the increased power compensate to keep them the same?

To be clear, I'm NOT saying the Auto-Rifle is 6.8mm.  I'm saying this particular technology leap could easily explain how you get to the Auto-Rifle (4/4) from the "Vintage" Auto-Rifle (2/3).

I didn't say you did and I can see how weapons get more powerful. But doesn't some of that depend on the ammo?
 

And as far as the mechanics, AP and BD are separate from the burst rate.  Single shots have the same AP and BD as bursts, and bursts simply increase the damage a particular weapon does at the TW scale (AToW Companion page 171 for that; the mechanic is different at AToW scale: AToW page 179 refers).

That's always confused me. In part because I have a hard time with AToW. If I fire a full burst from an Auto-Rifle at a tank, How many rounds hit and what's the damage? And in TW, does the Auto-Rifle have 30 shots doing .52 damage each or does it have 2 bursts doing .52 damage each? Why not just list the weight and damage of ammo fired per turn? Does a 6 shot Revolver fire all 6 shots for .17, or is that 6 .17 shots? I largely end up ignoring it or using bursts but it's still annoying.

[Daryk]

BD doesn't go up from increased rate of fire, TW scale damage does.  They are two different things.

Damage down range absolutely depends on ammo, but if you increase the propellant, you may need a heavier barrel, block, etc.  This particular technology advance gets around that.

If you fire a burst weapon at a tank at TW scale, the number of rounds that hit is irrelevant.  The burst rating is subsumed into the conversion formula.  The Auto-Rifle at TW scale has two bursts of 15 in a 30 round magazine (which can be made into a 45 round magazine with the Companion customization rules very easily, and for not that many C-Bills... hence my AR+ thread).  To answer your explicit question, it's two bursts that do 0.52 damage each.  Listing the weight of ammo and damage for each weapon would require more columns in the table that really aren't necessary.

In the case of the Revolver specifically, it's damage is reduced by the Reload Factor.  A Revolver only has 6 shots, so it's damage is 60% of what a 4/4 weapon with 10 shots would be.  No, I don't think Reload Factor is quite right, but that's a FAR different complaint, and one I partially addressed with my AR+ and "Adjusting Reload Factor" threads linked in my sig block.

[RifleMech]

BD doesn't go up from increased rate of fire, TW scale damage does.  They are two different things.

Which is confusing. If I fire a burst at a mech in AToW? Why wouldn't more rounds do more damage? and if not why does it in TW?

Damage down range absolutely depends on ammo, but if you increase the propellant, you may need a heavier barrel, block, etc.  This particular technology advance gets around that.

This is where I missed something. If a 5.56 rifle fires plastic rounds instead of brass, what happens? Same range and damage? More?
What if plastic rounds and brass rounds were mixed?

If you fire a burst weapon at a tank at TW scale, the number of rounds that hit is irrelevant.  The burst rating is subsumed into the conversion formula.  The Auto-Rifle at TW scale has two bursts of 15 in a 30 round magazine (which can be made into a 45 round magazine with the Companion customization rules very easily, and for not that many C-Bills... hence my AR+ thread).  To answer your explicit question, it's two bursts that do 0.52 damage each.  Listing the weight of ammo and damage for each weapon would require more columns in the table that really aren't necessary.

If firearms in TW only fire bursts, why list individual shots? Just like how many bursts and what that ammo weights. (Auto-Rifle 2 .48kg)

In the case of the Revolver specifically, it's damage is reduced by the Reload Factor.  A Revolver only has 6 shots, so it's damage is 60% of what a 4/4 weapon with 10 shots would be.  No, I don't think Reload Factor is quite right, but that's a FAR different complaint, and one I partially addressed with my AR+ and "Adjusting Reload Factor" threads linked in my sig block.

Is that a 6 round burst or 6 individual shots?

[Daryk]

It appears you didn't read the AToW page 179 reference.  The mechanic in AToW is that damage (not the BD of the weapon) goes up by 1 point per Margin of Success, up to a maximum of the number of rounds fired.  In contrast, the Companion conversion formula accounts for burst fire in the Damage Factor calculation.

If a 5.56 round that uses plastic instead of brass has the same amount of propellant and same weight bullet, it will do the same damage, but weigh 30% less.  If you mix plastic and brass rounds, you're probably violating every manufacturer warranty ever (and that assumes you don't have to change barrels to make it work).  As a game mechanic, I would just give you a bit less weight savings.

Many weapons only fire single shots.  The Companion formula is built to convert them all, whether single shot or burst of any size.

In the specific case of the Revolver, it's six individual shots.  Only weapons with a listed Burst rating fire bursts.

[RifleMech]

It appears you didn't read the AToW page 179 reference.  The mechanic in AToW is that damage (not the BD of the weapon) goes up by 1 point per Margin of Success, up to a maximum of the number of rounds fired.  In contrast, the Companion conversion formula accounts for burst fire in the Damage Factor calculation.

Read it. Don't always understand it. For example, the damage is based on the BD and it goes up depending on the Margin of Success. Standard damage goes up .25 damage per point of MoS. Burst goes up 1 point per MoS up to the max number of shots fired. So the BD does go up. Beyond that things get fuzzy. It doesn't apply to Vehicles does it?

If a 5.56 round that uses plastic instead of brass has the same amount of propellant and same weight bullet, it will do the same damage, but weigh 30% less.  If you mix plastic and brass rounds, you're probably violating every manufacturer warranty ever (and that assumes you don't have to change barrels to make it work).  As a game mechanic, I would just give you a bit less weight savings.

Okay but brass reduces the heat from the rounds fired. The video said that the rounds used the heat to be more powerful and the plastic stayed cool. So you'd either be stressing the weapon or the amount of propellant was reduced. I would hope the latter but maybe they make rounds for older gun and newer guns and read the package so you don't buy the wrong one. As for mixing? Probably but then just using the plastic probably would too. But if they function the same, other than heat, there shouldn't be a problem. Right?  As for game rules, I'd go with things stay the same but more ammo for the weight.

Many weapons only fire single shots.  The Companion formula is built to convert them all, whether single shot or burst of any size.

In the specific case of the Revolver, it's six individual shots.  Only weapons with a listed Burst rating fire bursts.

It seems written for single shot or full burst. I  don't doubt smaller bursts could be figured out but we're really going to need a spreadsheet for them.  AP/BD vs BAR and TW damage per shots fired.

So a Revolver fires 6 .17 damage shots. 1 shot per turn so it takes a full minute to empty the Revolver? And the Auto-Rifle is firing a .52 15 round burst every turn unless it fires a single shot for .17?

[Daryk]

I'm not sure what you mean by "applies to vehicles".  BD stays the same, but any individual shot can do more damage depending on the MoS.

The video is clear in stating that plastic is an insulator, which keeps the block cool when compared to brass which is a conductor.  It's the outside of the plastic that stayed cool.  Basically, more heat was transferred to the propellant, meaning higher muzzle velocity.  And yes, I said earlier you could choose to go with more ammo with the weight savings, or apply that weight savings to more power.  The latter would appear to be what the Auto-Rifle did, since the ammo weighs the same as 5.56.

I do use a spreadsheet to calculate burst damage, so varying burst size is no problem.  I've linked that particular sheet elsewhere, more than once.

You are correct about 6x0.17 shots, and that a full 15 round burst from an Auto-Rifle is 0.52 compared to its own single-shot damage of 0.17.

[RifleMech]

I'm not sure what you mean by "applies to vehicles".  BD stays the same, but any individual shot can do more damage depending on the MoS.

That answers one question. How about small support vehicles? They can mount the same weapons as infantry. Or larger vehicles and Mechs. Does their damage go up with the Mos?

The video is clear in stating that plastic is an insulator, which keeps the block cool when compared to brass which is a conductor.  It's the outside of the plastic that stayed cool.  Basically, more heat was transferred to the propellant, meaning higher muzzle velocity.  And yes, I said earlier you could choose to go with more ammo with the weight savings, or apply that weight savings to more power.  The latter would appear to be what the Auto-Rifle did, since the ammo weighs the same as 5.56.

I remember that part but I also remember that heat was bad and that the brass helped cool the gun. So if the plastic rounds didn't have reduced propellant, wouldn't the heat and increased power damage the gun? I suppose it could be okay for single shots from more modern guns but vintage guns? or bursts?

I'm not sure it's one or the other here. Just changing the casing made for a more powerful round. The heat burned propellant more efficiently or something. I didn't get that part. But it was the change in casing that made the rounds lighter. If the propellant is reduced too wouldn't the rounds be lighter still, meaning even more rounds for the same weight? And wouldn't the propellant have to be reduced or the weapon get overstressed and hot?

I do use a spreadsheet to calculate burst damage, so varying burst size is no problem.  I've linked that particular sheet elsewhere, more than once.

Cool! I must have missed that. Does it work with older excel programs? 

You are correct about 6x0.17 shots, and that a full 15 round burst from an Auto-Rifle is 0.52 compared to its own single-shot damage of 0.17.

   Cool! 

You do get what I was saying about how rounds can change the gun, right?  If modern rounds are made to work in older guns, which guns are vintage? And if a vintage weapon can be "upgraded" shouldn't that be reflected in the weapons stats?

[Daryk]

You use the AToW rules when you're playing AToW scale, and the TW scale rules when you're playing that.  It's determined by what you're playing, not the platform.  "Small support vehicles" exist in both.

Brass carries a small amount of heat with it when it's ejected, but conducts some to the block and rest of the weapon until it is.  Plastic carries more away when it's ejected because it's a much worse conductor of heat than brass.  Does that make sense?

The point the video was making was that 6.8mm rounds made with plastic casing were 30% lighter than 5.56mm ones with brass.  AND that those rounds had a heavier bullet and higher muzzle velocity.  Seriously, that's the mind blowing improvement we're seeing here at TL C in 2021.  That's why I linked the video here.

The spreadsheet should work with older versions.  The most advanced thing I used was conditional formatting.  Do you need a link to it, or have you seen it in the other conversations monbvol and I have had?

The point the video was making was that rounds engineered with backward compatibility in mind could result in weight savings for ammunition.  MY point was that if you took that technology and applied it to more power instead, you could achieve more power with the same weight.  I hope I'm making sense here...

[monbvol]

The caveat is that more power almost always means more pressure on the bolt, barrel, and possibly other inner workings that can significantly shorten a weapon's operational life.

For my sheet I'd recommend the one in my AU development thread right now though.  The one I have elsewhere I am pretty sure has a math error for ordinance support weapons.  If I remember I'll fix that when I get home.

[Daryk]

I'll confess to being a little lazy there... when I say "plastic", I really mean "composite".  The casings can handle the increased pressure and heat so the bolt and barrel don't have to.  The barrel just has to be big enough to pass the bullet.  It really is revolutionary technology application (since the tech has actually been around a while).

[RifleMech]

You use the AToW rules when you're playing AToW scale, and the TW scale rules when you're playing that.  It's determined by what you're playing, not the platform.  "Small support vehicles" exist in both.

However, one should be able to convert between the two. So what's the most damage an Auto-Rifle can do when mounted on a small vehicle and fired at a larger vehicle or Mech? Is it the same as when a trooper fires at the same target?

Brass carries a small amount of heat with it when it's ejected, but conducts some to the block and rest of the weapon until it is.  Plastic carries more away when it's ejected because it's a much worse conductor of heat than brass.  Does that make sense?

No. Sorry. It seems opposite of what was said about plastic.

The point the video was making was that 6.8mm rounds made with plastic casing were 30% lighter than 5.56mm ones with brass.  AND that those rounds had a heavier bullet and higher muzzle velocity.  Seriously, that's the mind blowing improvement we're seeing here at TL C in 2021.  That's why I linked the video here.

It is a big improvement and pretty cool. They do seem to have 5.56mm rounds though. Which makes me wonder what happens if you use them in a 5.56mm rifle made to shoot brass rounds. Do they intentionally have less propellant so not to stress the gun?

The spreadsheet should work with older versions.  The most advanced thing I used was conditional formatting.  Do you need a link to it, or have you seen it in the other conversations monbvol and I have had?

A link would be cool. Thanks 

The point the video was making was that rounds engineered with backward compatibility in mind could result in weight savings for ammunition.  MY point was that if you took that technology and applied it to more power instead, you could achieve more power with the same weight.  I hope I'm making sense here...

Okay. Backwards compatible. More ammo. The rest stays the same. Cool.  More power for same weight? Need a different gun. Which is what they did.

I'll confess to being a little lazy there... when I say "plastic", I really mean "composite".  The casings can handle the increased pressure and heat so the bolt and barrel don't have to.  The barrel just has to be big enough to pass the bullet.  It really is revolutionary technology application (since the tech has actually been around a while).

I'm pretty sure I saw in one of the videos that brass getting hot and removing heat when ejected was a good thing for the gun. Heat building up in the gun was bad for its parts and bad for ammo that was being loaded. The plastic composite rounds don't remove heat from the gun. That heat helps make the round more powerful.
For plastic to work in older guns the power would have to be reduced so as not to be so hot and cause problems for the gun. Along with being more power than the gun can handle. Right?

The caveat is that more power almost always means more pressure on the bolt, barrel, and possibly other inner workings that can significantly shorten a weapon's operational life.

For my sheet I'd recommend the one in my AU development thread right now though.  The one I have elsewhere I am pretty sure has a math error for ordinance support weapons.  If I remember I'll fix that when I get home.

That's what I thought.

Link please? With my luck I'll find the other one. Thanks

[monbvol]

I'll confess to being a little lazy there... when I say "plastic", I really mean "composite".  The casings can handle the increased pressure and heat so the bolt and barrel don't have to.  The barrel just has to be big enough to pass the bullet.  It really is revolutionary technology application (since the tech has actually been around a while).

Sure it can absorb some of the pressure but not all of it, that is what is propelling the bullet down the barrel after all.

Looks like the error was confined to an early version of my combining of my infantry weapons to TW scale and my infantry armor kits to TW scale conversion sheets.

For the stand alone weapons sheet first post in this thread should have something usable.

If that fails for some reason I have an in progress final product towards the end of this thread that I know works but is full of my full conversion AU stuff.

[Daryk]

Riflemech:

1) It depends on what you're playing.  Are you playing AToW or TW?

2) Here's how heat transfer works (I am, in fact, a physicist): good conductors (like brass) transfer heat quickly.  Quickly enough to transfer it to the block, and the outside of the casing (meaning they both feel hot after a shot).  Poor conductors transfer heat slowly, meaning they absorb more heat into their mass and only slowly radiate it outward.  This means a plastic (really, composite) casing will absorb more heat into itself, and only slowly transfer it to its outer surface, and thus the block.  This is why both the block and outside of the casings feel cool to the touch immediately after firing in the video.  Am I making sense yet?

3) I haven't read anything about 5.56 composite rounds, so I'm afraid I can't answer that question definitively, but I believe most current 5.56 rifles have sufficient overengineering to be able to fire at least SOME rounds before requiring replacement.

4) Link as requested: https://bg.battletech.com/forums/fan-designs-rules/fixing-the-atow-companion-conversion-to-tw-for-mech-weapons/msg1709504/#msg1709504

5) At least one point got through!

6) No, not right.  As I explained above, the composite casing absorbs more heat into its mass vice conducting it to its exterior surface, and thus the gun.  When the casing is ejected, it takes all that absorbed heat with it, and that is MORE than the brass carries with it.

7) That one's monbvol's, and he already answered it...

[RifleMech]

Looks like the error was confined to an early version of my combining of my infantry weapons to TW scale and my infantry armor kits to TW scale conversion sheets.

Found the link. Yay! It's not what I was looking for though. I was looking for something that says how much damage per weapon is done per round to BAR armor and in TW.

Riflemech:

1) It depends on what you're playing.  Are you playing AToW or TW?

That's just it. There shouldn't be one of the other as you should be able to go back and forth. Right now an Auto-Rifle in AToW is far more powerful than one in TW. And that's not including the fact that AToW turns are twice as fast.

2) Here's how heat transfer works (I am, in fact, a physicist): good conductors (like brass) transfer heat quickly.  Quickly enough to transfer it to the block, and the outside of the casing (meaning they both feel hot after a shot).  Poor conductors transfer heat slowly, meaning they absorb more heat into their mass and only slowly radiate it outward.  This means a plastic (really, composite) casing will absorb more heat into itself, and only slowly transfer it to its outer surface, and thus the block.  This is why both the block and outside of the casings feel cool to the touch immediately after firing in the video.  Am I making sense yet?

Sorry. Went right past me. If the casing is a poor conductor of heat, how's it remove the heat?

3) I haven't read anything about 5.56 composite rounds, so I'm afraid I can't answer that question definitively, but I believe most current 5.56 rifles have sufficient overengineering to be able to fire at least SOME rounds before requiring replacement.

The video mentioned them but didn't show them in use. Single shots makes sense. Warning labels "Do Not Fie At Full Auto" makes sense. Their being made backwards compatible so the older guns don't blow makes sense. A warning label, "Not made for these firearms with a list." makes sense.

4) Link as requested: https://bg.battletech.com/forums/fan-designs-rules/fixing-the-atow-companion-conversion-to-tw-for-mech-weapons/msg1709504/#msg1709504

Thanks!   Unfortunately, I can't open it with the good excel. The new one does but I can't do anything. Not that I understand it.
It doesn't seem to be what I'm looking for either.

5) At least one point got through!

WhooHoo!  Where's my donut? 

So how do we handle the M240 and other weapons where parts are changed? Same everything but amount of ammo?

6) No, not right.  As I explained above, the composite casing absorbs more heat into its mass vice conducting it to its exterior surface, and thus the gun.  When the casing is ejected, it takes all that absorbed heat with it, and that is MORE than the brass carries with it.

 
If the casing is absorbing the heat and taking that heat with it when it leaves, how can it transfer it to the gun? And why isn't it hot?


Watched the video again. It said that the polymer is an insulator more energy is used to push the projectile. They use 10% less propellant to do the same job.  It's about 7:50 minutes in. That would explain how it's backwards compatible. Less propellant used for the same job.

[Daryk]

The compatibility question is for TPTB.  I'm trying to solve it one problem at a time (with two locked threads to show for it so far).

Ok, physics take two: heat transfer takes time.  It takes less time through the bulk of good conductors than poor ones.  The walls of casings don't have much bulk, but the principles are the same.  Heat generated inside a brass casing is conducted quickly through the casing walls, and to the block from there.  Heat generated inside a composite casing isn't absorbed as quickly (meaning more goes to the propellant gasses, as the video described), and the that IS transferred to the bulk of it doesn't make it to the exterior of the casing before the casing is ejected.  That means the heat that WAS absorbed by the composite casing is ejected with the casing.  How's that?

I'm not really sure what you're saying about Excel... you have a version that will open it, but can't edit for some reason? 

I'm much less sure about the M240.  My impression was that it was firing the 6.8mm ammo instead of its regular 7.62mm.  That would be less damage.

What you're describing there at the end is exactly how it works.  The composite casing is taking MORE heat with it than the brass, and NOT transferring it to the gun.  That's the whole point of the design.  It keeps the gun cooler than brass casings do.  Also, compare to muzzle loaders that have to be cooled by sponging them out before reloading.  There is NO casing for those weapons, so they need to be cooled between shots.

[Hellraiser]

It certainly could use caseless ammo, but I think TPTB were deliberately vague on that point.

I'm guessing standard cased ammo for the bog standard AR.

That 3mm GDL rifle from the 1st trilogy stood out for firing a Caseless+Explosive ammunition.

But it was "special/different".

So I'm sticking with standard AR is cased. 

[RifleMech]

The compatibility question is for TPTB.  I'm trying to solve it one problem at a time (with two locked threads to show for it so far).

You'd think they'd want their games to be compatible though.    I try to ask questions and don't get any where either. 

Ok, physics take two: heat transfer takes time.  It takes less time through the bulk of good conductors than poor ones.  The walls of casings don't have much bulk, but the principles are the same.  Heat generated inside a brass casing is conducted quickly through the casing walls, and to the block from there.  Heat generated inside a composite casing isn't absorbed as quickly (meaning more goes to the propellant gasses, as the video described), and the that IS transferred to the bulk of it doesn't make it to the exterior of the casing before the casing is ejected.  That means the heat that WAS absorbed by the composite casing is ejected with the casing.  How's that?

But the casing is cool so where's the heat it absorbed?  It sounds like the heat when down the barrel but because there's less propellant the heat isn't enough to cause damage. And since the heat went down the barrel the ejected casings are cool.

I'm not really sure what you're saying about Excel... you have a version that will open it, but can't edit for some reason? 

The versions of office that come with windows now, are read only. They don't work unless you either sign in, so microsoft sees even more, or you pay for them.

So I use an older version. It works fine but doesn't open newer formats.

I'm much less sure about the M240.  My impression was that it was firing the 6.8mm ammo instead of its regular 7.62mm.  That would be less damage.

Makes sense.

What you're describing there at the end is exactly how it works.  The composite casing is taking MORE heat with it than the brass, and NOT transferring it to the gun.  That's the whole point of the design.  It keeps the gun cooler than brass casings do.  Also, compare to muzzle loaders that have to be cooled by sponging them out before reloading.  There is NO casing for those weapons, so they need to be cooled between shots.

But the casings are insulators not conductors. 

[Daryk]

The outside of the casing is cool.  Don't stick your finger inside it.  And you are correct that more energy was directed down the barrel.

Insulators are basically just really (REALLY) slow conductors.

I'll see about saving the spreadsheet in an older format.  How far back do I need to go?

[RifleMech]

The outside of the casing is cool.  Don't stick your finger inside it.  And you are correct that more energy was directed down the barrel.

Insulators are basically just really (REALLY) slow conductors.

I'll see about saving the spreadsheet in an older format.  How far back do I need to go?

I thought so. Why would I do that?
Yay!

Okay.

Thanks. I'm not sure. The Excel I use is pretty old. From Office 97. It does what I want, except open newer formats. Which usually isn't a problem. I do know monbvol's worked. Looking at them in the folder they don't even have the same icon. Weird.

[Daryk]

Ok... I'll see if I can reach that far back with a "Save As" after work tonight.

[monbvol]

Probably because I use OpenOffice.  I really need to switch to LibreOffice one of these days though.

[Daryk]

Ok, the Save As worked, but Excel told me the conditional formatting will be screwed up.  Sorry about that.  It's pretty handy to see where the break points are.  I saved it with "No" for Splash Damage and Incendiary effects, and 1 Burst with enough ammo to avoid a penalty from Reload Factor.  Please let me know if it works for you.

[RifleMech]

Ok, the Save As worked, but Excel told me the conditional formatting will be screwed up.  Sorry about that.  It's pretty handy to see where the break points are.  I saved it with "No" for Splash Damage and Incendiary effects, and 1 Burst with enough ammo to avoid a penalty from Reload Factor.  Please let me know if it works for you.

It worked. I'm not sure I follow it but it worked. Thanks  

Probably because I use OpenOffice.  I really need to switch to LibreOffice one of these days though.

I wouldn't mind using LibreOffice. It was on a different computer but it isn't available. 

[Daryk]

If you're having trouble making sense of it, just ask! 

[RifleMech]

  Asking. Sorry. It's not making sense to me.

[Daryk]

So what are you not following?  The inputs to the formula are the weapon's AP and BD, its characteristics (incendiary, splash), burst value (rounded per Herb's errata), and number of reloads.  The output in the cells of the able is the TW damage.

[RifleMech]

I'm presuming the formula is the conversion from AToW to TW, which I can follow. Slowly. I'm not sure what to do with the spreadsheet. 

[Daryk]

Adjusting the characteristics changes the values in the table.  Splash and incendiary are simply additions to a multiplier.  Burst is a little more complicated, but basically the same thing: it adjusts a multiplier.  Reload factor only reduces damage if you have less than 10 shots for a "standard" weapon, or 3 if it's support (which you switch with the "Type" dropdown).

[RifleMech]

Sorry. I know it makes sense to you but I'd need step by step instructions for it.

[Daryk]

The cells next to "Incendiary" and "Splash" (B1 and D1) are drop downs with Y or N for Yes or No.

The cell next to "Burst" (F1) is just a number field that you enter whatever burst value you want into.

The cell next to "Type" is a dropdown with "Std" for Standard weapons and "Sup" for Support.

The cell next to "Shots" is another number field where you enter the size of one "reload" (magazine).  It factors into Reload Factor (which is calculated... don't mess with the cells to the right of that) along with the Type above.

Those are the only things you need to enter.  The rest of the table is simply the computed TW scale damage for whatever AP and BD you cross reference (AP is vertical, BD is horizontal).  Beyond 18 BD, I only entered multiples of 6 (which match the TW to AToW scale conversion) to see how close they were at AP 10.

Does that make sense?

[RifleMech]

So these are numbers I'm supposed to put into the AToW Conversion formula?

[Daryk]

What I outlined above are basically that, yes.  The only numbers that go straight into the formula are Burst and Shots (which you enter), and AP and BD (which are just part of the table).

Splash and Incendiary characteristics add numbers to multipliers (Incendiary a +2 to AP in the Penetration Factor, Splash a +1 to the term that multiplies BD for the Damage Factor).  Type tells the sheet which Reload Factor formula to use.

[Daemion]

Doesn't matter if they do, Armor weakens after each successive hit regardless if it penetrates or not. This is why things like motorcycle helmets should be checked after a drop from a good height. Armor designed to handle stronger impacts either need to be incredibly thick and heavy to resist that weakening, or use self destruction to handle it. Battletech armor is handled very much of the self-sacrificing variety which means it can be degraded by multiple small hits.

The Highlighted for emphasis gets this reply: I see BT armor as a combination of deflective and ablative properties. Otherwise, there wouldn't be such high to-hit values in-game.  You'd be rolling location and assigning damage only.  Which means it lasts longer than what you would think it should. 

I found my justification for how I see things working. 

[RifleMech]

What I outlined above are basically that, yes.  The only numbers that go straight into the formula are Burst and Shots (which you enter), and AP and BD (which are just part of the table).

Splash and Incendiary characteristics add numbers to multipliers (Incendiary a +2 to AP in the Penetration Factor, Splash a +1 to the term that multiplies BD for the Damage Factor).  Type tells the sheet which Reload Factor formula to use.

Okay. Thanks.

[Daryk]

Victory?   

[RifleMech]

I'm still not sure what to plug in where but that's okay. I'm not really sure how to do anything with AToW.

[Daryk]

Ok, here's an example:

For a bog standard Auto-Rifle, you would enter N for Incendiary, N for Splash, 15 for Burst, Std for Type, and 30 for Shots.  Then you'd look in the table cross-referencing 4 AP and 4 BD.  The value in that cell is 0.52, exactly what you'd expect it to be.

Does that help?

[RifleMech]

 

Sorry. No. I know it makes sense for you but I can't find a .52 on the table. Where's the AP and BD?

[Daryk]

The AP are in column A (from Row 2 to 12), and BD is in row 2.  It's an AP vs. BD table...

[RifleMech]

Okay...

And on to more stupid questions.

Infantry weapons are either single shot or burst right? So if two single shot guns both have the same AP/BD they should do the same damage in TW, right? So why don't they in TW? Nearest I can figure is that total payload is factored into the TW damage but if they're only firing single shots, the total payload shouldn't matter. Right? Or am I missing more things?

[Daryk]

It sounds like you're discussing Reload Factor.  I agree it's odd, but it is part of the conversion.  Disposable weapons get around Reload Factor but must track ammo.  Personally, I think tracking ammo is better than the abstraction of Reload Factor.

[monbvol]

The conversion also assumes that a burst capable weapon is always firing a full burst.

So yes if you fudged the conversion process two different weapons with the same AP and BD if firing a single shot will work out the same.

[RifleMech]

It sounds like you're discussing Reload Factor.  I agree it's odd, but it is part of the conversion.  Disposable weapons get around Reload Factor but must track ammo.  Personally, I think tracking ammo is better than the abstraction of Reload Factor.

Which is weird because if the weapon only fires a single shot, why does it matter how much ammo it has? When used by infantry. Small vehicles track ammo but still, it's only firing a single shot. Not all the rounds.

The conversion also assumes that a burst capable weapon is always firing a full burst.

So yes if you fudged the conversion process two different weapons with the same AP and BD if firing a single shot will work out the same.

That's what I thought but looking in AToW they both had the same AP/BD but the ammo was different. TW gives them different damages.

[Daryk]

Which specific weapons are you looking at? 

[Nicoli]

The Highlighted for emphasis gets this reply: I see BT armor as a combination of deflective and ablative properties. Otherwise, there wouldn't be such high to-hit values in-game.  You'd be rolling location and assigning damage only.  Which means it lasts longer than what you would think it should. 

I found my justification for how I see things working.

Deflective and Ablative properties do not work together because they require competing goals. Lets say you take ablative armor, it is going to be designed to take the force and keep it internal to the armor. Now lets take Rigid armor where deflection is often considered the goal. The idea there is to have as little energy as possible kept. So if you put a layer of Ablative armor on top of rigid armor you end up with effectively a free ballistic cap (a malleable metal cap to grip onto the armor) for your enemies projectile. If you put armor designed to deflect on top it will most likely do nothing though you do run the risk of preventing the ablative armor from properly absorbing the round and dissipating the energy.

Rigid armor also has the issue that once it is attacked by a round that can defeat it, it offers little to no protection. This is why in things like tank design, armor would be designed in steps. If you enemy only has 57mm and 75mm guns, and if 2" would stop a 57mm, and 4" would stop a 75mm. you would never put 3" of armor on a vehicle because while it would still stop the 57mm round it would still fail to stop the 75mm round while just weighing the vehicle down reducing mobility and straining the suspension and engine.

If you really want to assume ultra-accurate predictive targetting systems in the battletech world, then the most likely assumption and is actually backed up by the game mechanics, is that Mechs armor is designed like WWII battleships in an all and nothing scheme. That means most of the outer surface of the mech is not armor but a thin layer of either plastic, composite, or sheet metal that is just used to provide form and keep the weather out. The actual armor is under the "Skin" in most places only covering the stuff that matters.

[Nicoli]

3) I haven't read anything about 5.56 composite rounds, so I'm afraid I can't answer that question definitively, but I believe most current 5.56 rifles have sufficient overengineering to be able to fire at least SOME rounds before requiring replacement.

6) No, not right.  As I explained above, the composite casing absorbs more heat into its mass vice conducting it to its exterior surface, and thus the gun.  When the casing is ejected, it takes all that absorbed heat with it, and that is MORE than the brass carries with it.

I'll answer this as a gunsmith

The heat absorption of the shell casing is a non-factor in firearm design. So many things will fail quite catastrophically in a firearm before breach temperature is ever a concern. For example your going to see a barrel failure due to the combined friction of the rifling and the heat from the propellant burning all the way down the barrel long before the chamber will fail. Also the shell casing provides no containment support to the chamber. We have classically used brass casings because of it's elasticity allowing it to expand during firing consistently onto the walls of the chamber while at the same time returning to it's slightly smaller size to allow for easy in loading a live round and extracting the spent casing.  The reason that we haven't used plastic/composite materials in rifle rounds is that until recently we couldn't produce good cheap plastic/composites that could handle the firing cycle of of a casing, general wear, tear, and abuse, and be reliable. plastic/composites have been used in shotgun shells as the tolerances for failure are much lower then in a rifle especially semi-automatics.

as for composite rounds or specifically bullets, you can shoot most of them out of a rifle with no issue, though they are generally LESS effective not more. This comes from the fact that for a round you generally are looking for firing either more mass out of a barrel or the same mass with more velocity, with the latter generally being the more preferable option. There is no composite that I am aware of that is more dense then it's component parts. That means composite bullets are lighter and as such require a physically larger projectile to get the same effect. You would be better off going for either a sub-caliber projectile with a higher density round fired at high velocity such as modern DU and tungsten penetrators, going with better/more propellant to increase velocity, or going into a specially designed round with some sort of special effect being it passive (hollowpoint) or active (HEAP, HESH, Inc., etc...).

[Daryk]

Have you watched any of Task and Purpose's other videos?  They have a few on this topic...

[monbvol]

Which is weird because if the weapon only fires a single shot, why does it matter how much ammo it has? When used by infantry. Small vehicles track ammo but still, it's only firing a single shot. Not all the rounds.

That's what I thought but looking in AToW they both had the same AP/BD but the ammo was different. TW gives them different damages.

The biggest reason an Autorifle has a different damage than a Bolt Action Rifle as an example since both are AP4 BD4 ballistic weapons does simply come down to the fact that the Autorifle is capable of firing bursts and the conversion process in AToW Companion by default always assumes it is firing full burst.

As to why magazine size matters even for something like a Bolt Action Rifle is to make the distinction between maximum rate of fire(if you never had to stop and reload the weapon even via some sort of autoloader process) and practical rate of fire.  Even single fire weapons akin to the Bolt Action Rifle tend to have a noticeably higher maximum rate of fire versus practical rate of fire.  Situations where everyone is reloading at the same time in even an infantry squad are pretty rare.  As is everyone firing at even full practical rate of fire.  These factors are actually somewhat considered desirable in the field as they do tend to minimize how vulnerable troops are.

That is the other big reason why the Bolt Action Rifle will work out different.

As far as ammo being different, well that makes sense as real world Assault Rifles use a round that has less propellant behind them even if it is as big around in diameter as a full rifle round.

How much this might make a difference in AP and BD terms I'm not enough of an expert on the matter to say with a lot of authority.  Battletech clearly uses different ammunition than the current real world though.

[Nicoli]

As to why magazine size matters even for something like a Bolt Action Rifle is to make the distinction between maximum rate of fire(if you never had to stop and reload the weapon even via some sort of autoloader process) and practical rate of fire.  Even single fire weapons akin to the Bolt Action Rifle tend to have a noticeably higher maximum rate of fire versus practical rate of fire.  Situations where everyone is reloading at the same time in even an infantry squad are pretty rare.  As is everyone firing at even full practical rate of fire.  These factors are actually somewhat considered desirable in the field as they do tend to minimize how vulnerable troops are.

Magazine size is fairly irrelevant to practical rate of fire. Any relatively skilled individual which is what we should expect in these games should be able to swap magazines around on any competently designed firearm at a rate that makes it effectively irrelevant, 1 second or less. Top shooters can swap a magazine so quickly they'll have the next round off before the first magazine hits the ground. If you want to see some real insanity here is Jerry Miculek with a revolver! https://youtu.be/WzHG-ibZaKM

As far as ammo being different, well that makes sense as real world Assault Rifles use a round that has less propellant behind them even if it is as big around in diameter as a full rifle round.

Uh, no... This is entirely inaccurate. Rifles of all types use standardized ammo. While you can see custom loads for firearms these are done on the small scale normally by individual users for specific reasons. These standards are based on the burn rate of a propellant, barrel length, and Chamber specifications. For example an Ar build firing a .300 blackout round will have a shorter barrel then a standard 5.56. because the propellant in a .300 blackout burns at a faster rate. Modern military rifles use smaller caliber rifle ammunition due to weight and size reasons as it is generally better to have more rounds over less available in combat. Hunters used heavier rounds as we want to prevent an animal from suffering and us being generally lazy and not wanting to having to track a wounded animal down.

How much this might make a difference in AP and BD terms I'm not enough of an expert on the matter to say with a lot of authority.  Battletech clearly uses different ammunition than the current real world though.

Wouldn't make a difference at all. Only thing that would make a difference is Weight of the projectile, aerodynamic drag of the projectile, and muzzle velocity. How you get those would be irrelevant.

Edit: This is assuming the projectiles don't have any extra effects like some form of explosive or Incendiary capabilities added.

[monbvol]

Magazine size is fairly irrelevant to practical rate of fire. Any relatively skilled individual which is what we should expect in these games should be able to swap magazines around on any competently designed firearm at a rate that makes it effectively irrelevant, 1 second or less. Top shooters can swap a magazine so quickly they'll have the next round off before the first magazine hits the ground. If you want to see some real insanity here is Jerry Miculek with a revolver! https://youtu.be/WzHG-ibZaKM
Uh, no... This is entirely inaccurate. Rifles of all types use standardized ammo. While you can see custom loads for firearms these are done on the small scale normally by individual users for specific reasons. These standards are based on the burn rate of a propellant, barrel length, and Chamber specifications. For example an Ar build firing a .300 blackout round will have a shorter barrel then a standard 5.56. because the propellant in a .300 blackout burns at a faster rate. Modern military rifles use smaller caliber rifle ammunition due to weight and size reasons as it is generally better to have more rounds over less available in combat. Hunters used heavier rounds as we want to prevent an animal from suffering and us being generally lazy and not wanting to having to track a wounded animal down.

Wouldn't make a difference at all. Only thing that would make a difference is Weight of the projectile, aerodynamic drag of the projectile, and muzzle velocity. How you get those would be irrelevant.

Edit: This is assuming the projectiles don't have any extra effects like some form of explosive or Incendiary capabilities added.

I have seen that video before and it is certainly impressive but it is not what you can expect under combat conditions carrying combat loads.

Part of what determines if a weapon is an Assault Rifle or Automatic Rifle is if it uses an intermediary cartridge or not.  Like AK-47 versus BAR:

AK-47 uses 7.62x39mm rounds.  .30-06, a full size rifle round, is 7.6-7.8mm depending on where you measure and has an overall length of 85mm.

The rest I certainly defer to your expertise.

[CVB]

Part of what determines if a weapon is an Assault Rifle or Automatic Rifle is if it uses an intermediary cartridge or not.  Like AK-47 versus BAR:

AK-47 uses 7.62x39mm rounds.  .30-06, a full size rifle round, is 7.6-7.8mm depending on where you measure and has an overall length of 85mm.

It's the case with AK-47/AKM as well as the original assault rifle, the StG44, and the M2 carbine, which all use(d) shorter, full diameter ammunition (compared to their "partners" Mosin-Nagant, Kar98k and M1 Garand). However, these were all early designs from the 1940s. Ever since, assault rifles have used smaller calibers like 5.56 or 5.45, while full power cartridges (typically 7.62x51 NATO) became the domain of battle rifles like the FN-GL, M14, G3 and later HK417, SCAR-H etc.

[monbvol]

It's the case with AK-47/AKM as well as the original assault rifle, the StG44, and the M2 carbine, which all use(d) shorter, full diameter ammunition (compared to their "partners" Mosin-Nagant, Kar98k and M1 Garand). However, these were all early designs from the 1940s. Ever since, assault rifles have used smaller calibers like 5.56 or 5.45, while full power cartridges (typically 7.62x51 NATO) became the domain of battle rifles like the FN-GL, M14, G3 and later HK417, SCAR-H etc.

Which is part of the distinction I am trying to make, obviously rather poorly.

All the more I'll say is I've watched some interesting two gun and even three gun competition matches where practical rate of fire was very much a thing even among the top competitors.  Which is still a far more forgiving environment for such things than real combat.

[RifleMech]

Which specific weapons are you looking at? 

Auto-Pistol (M&G)
Auto-Pistol (Nambu)

Both are 3B/4 and fire single shots but the M&G does .17 and the Nambu .21. I'm guessing the Nambu does more damage because it has more ammo but they're single shot weapons so more ammo shouldn't matter.

[Daryk]

Yes, Reload Factor is exactly what's causing that.  If you multiply 0.21 by 0.8 (8/10), you get 0.17 after rounding.

[RifleMech]

The biggest reason an Autorifle has a different damage than a Bolt Action Rifle as an example since both are AP4 BD4 ballistic weapons does simply come down to the fact that the Autorifle is capable of firing bursts and the conversion process in AToW Companion by default always assumes it is firing full burst.

As to why magazine size matters even for something like a Bolt Action Rifle is to make the distinction between maximum rate of fire(if you never had to stop and reload the weapon even via some sort of autoloader process) and practical rate of fire.  Even single fire weapons akin to the Bolt Action Rifle tend to have a noticeably higher maximum rate of fire versus practical rate of fire.  Situations where everyone is reloading at the same time in even an infantry squad are pretty rare.  As is everyone firing at even full practical rate of fire.  These factors are actually somewhat considered desirable in the field as they do tend to minimize how vulnerable troops are.

That is the other big reason why the Bolt Action Rifle will work out different.

As far as ammo being different, well that makes sense as real world Assault Rifles use a round that has less propellant behind them even if it is as big around in diameter as a full rifle round.

How much this might make a difference in AP and BD terms I'm not enough of an expert on the matter to say with a lot of authority.  Battletech clearly uses different ammunition than the current real world though.

I understand that bursts are going to do more damage it's the single shots I'm looking at. I get that not everyone will be reloading and firing at the same time but with 1 shot every 10 seconds that's a lot of time for other troops to be doing things. Its even weirder for small support vehicles. They're still firing single shots. That one has more ammo just means it can fire more turns. It shouldn't do more damage.

Yes, Reload Factor is exactly what's causing that.  If you multiply 0.21 by 0.8 (8/10), you get 0.17 after rounding.

Thought so! Thanks.   Which of course leads to why when only one shot is being fired?


And if I understood the rest a hunting rifle will do more damage per round but the assault rifle does more damage overall because more rounds are fired. Which makes sense to me. What I'm wondering, still, is about older rounds. I get that they might not have the armor penetration, maybe, but the rounds   

If my math is right, the muzzle velocity of the Brown Bess is 26% less than the AK-47 but the round fired is 2.3 times bigger. Surely that's going to give the person on the receiving end a very bad day. And that doesn't get into alternative loads either.

[Daryk]

Kinetic energy is proportional to the mass of the projectile, but the square of its velocity.  This is why muzzle velocity is more important.

[Nicoli]

I have seen that video before and it is certainly impressive but it is not what you can expect under combat conditions carrying combat loads.

Part of what determines if a weapon is an Assault Rifle or Automatic Rifle is if it uses an intermediary cartridge or not.  Like AK-47 versus BAR:

AK-47 uses 7.62x39mm rounds.  .30-06, a full size rifle round, is 7.6-7.8mm depending on where you measure and has an overall length of 85mm.

The rest I certainly defer to your expertise.

Yeah, he is an obvious outlier. But a most soldier can do a magazine swap in between targets.

The 7.62x39mm like most other combat rounds are selected for ammunition capacity first. With the days of bolt action weapons gone the tactic of fire and maneuver the size of the total round became more important then any other characteristic. More ammo was being used to suppress targets compared to actually kill them. So any round that can get the job done in a smaller package is better. The difference between a 7.62x39 and say the 7.62x54r at the practical combat ranges is negligible, but the weight difference is not.

One of the things, that sadly is the fault of movies, new media, and politicians is that there is no real difference between an Automatic Rifle and an Assualt Rifle. They are terms tossed around but are mostly just used as a refinement of an Idea. A BAR for example would for all intents and purposes be an assault rifle, yet is called an automatic rifle. There is nothing preventing a modern assault rifle from using a larger round, just no real point to it from a tactical perspective. So if anything you can say an Automatic rifle is the predecessor of the Assault Rifle.

And if I understood the rest a hunting rifle will do more damage per round but the assault rifle does more damage overall because more rounds are fired. Which makes sense to me. What I'm wondering, still, is about older rounds. I get that they might not have the armor penetration, maybe, but the rounds   

If my math is right, the muzzle velocity of the Brown Bess is 26% less than the AK-47 but the round fired is 2.3 times bigger. Surely that's going to give the person on the receiving end a very bad day. And that doesn't get into alternative loads either.

Well, part of the issue is that there is a threshold where putting more kinetic energy into a round actually does less damage in practice. This is a big issue with things like Railguns and why they most likely won't be shooting much faster then ballistic weapons in direct fire cases. The more kinetic energy a projectile has the tougher the target has to be to do any real damage. For example shoot a .50 BMG into a paper target and it makes a hole about 1-1.5in across. Put into some clay and watch it split the clay block. This is because the block of clay is substantial enough to provide resistance to the bullet which allows for kinetic energy to transfer to it from the bullet. It's another reason modern militarys went to smaller lighter rounds because there just wasn't a significant benefit to the extra kinetic energy.

[monbvol]

Yeah, he is an obvious outlier. But a most soldier can do a magazine swap in between targets.

Like I said I've seen plenty of two or three gun match videos where having to actually reload under far more stressful conditions than presented in that video, find/identify your target, and actually having to move about carrying your ammo with you made the practical rate of fire show up and be a real consideration.

The 7.62x39mm like most other combat rounds are selected for ammunition capacity first. With the days of bolt action weapons gone the tactic of fire and maneuver the size of the total round became more important then any other characteristic. More ammo was being used to suppress targets compared to actually kill them. So any round that can get the job done in a smaller package is better. The difference between a 7.62x39 and say the 7.62x54r at the practical combat ranges is negligible, but the weight difference is not.

One of the things, that sadly is the fault of movies, new media, and politicians is that there is no real difference between an Automatic Rifle and an Assualt Rifle. They are terms tossed around but are mostly just used as a refinement of an Idea. A BAR for example would for all intents and purposes be an assault rifle, yet is called an automatic rifle. There is nothing preventing a modern assault rifle from using a larger round, just no real point to it from a tactical perspective. So if anything you can say an Automatic rifle is the predecessor of the Assault Rifle.

That's exactly why part of the definition in a lot of circles includes using an intermediary round to be considered an Assault Rifle.

Well, part of the issue is that there is a threshold where putting more kinetic energy into a round actually does less damage in practice. This is a big issue with things like Railguns and why they most likely won't be shooting much faster then ballistic weapons in direct fire cases. The more kinetic energy a projectile has the tougher the target has to be to do any real damage. For example shoot a .50 BMG into a paper target and it makes a hole about 1-1.5in across. Put into some clay and watch it split the clay block. This is because the block of clay is substantial enough to provide resistance to the bullet which allows for kinetic energy to transfer to it from the bullet. It's another reason modern militarys went to smaller lighter rounds because there just wasn't a significant benefit to the extra kinetic energy.

Oh yeah I completely understand all of that.  The concept of over-penetration is something I actually quite understand.  As well as yes weight was an important part of the consideration of why intermediary rounds started becoming more popular.  Another contributing factor was that when nations really looked into it they found most combat just really did not require something effective beyond 500 meters.

Another interesting video from I think it was Inrange on youtube was Ian from Forgotten Weapons and his host talking about how accurate even Designated Marksman Rifles are even zeroed and put on rests and what the accuracy standards of WW2 or so were.  It was really quite interesting.

[SlightlyIrritatedCat]

Also when talking about damage in pre-smokeless firearms versus smokeless firearms there is a huge gulf due to changes in bullet manufacture and design to account for the different qualities of a smokeless cartridge.  For example nearly all the various rifles and carbines with pre-1886 centerfire brass were at between 1100 and 1600 fps.  1600fps was considered a very hot load.  Remember pre-smokeless you needed a big bore round in a service rifle to prevent fouling from causing problems even during a single battle.  Lack of velocity meant typically you were firing 10-13mm unjacketed round-nosed lead bullets somewhere between 300-500 grains.  Big soft slow moving bullets that would expand and mushroom like crazy.  For example a family trick when hunting hogs and bears is to put civil-war era style minie balls into shotgun shells with a rifled choke.  I've personally seen those type of rounds remove limbs, punch exit holes the size of a snack plate, and fling chunks of internal organs that weight two or three pounds out the other side of a hog or bear.  The old unjacketed lead blackpowder service rifles had very different terminal ballistics than a modern jacketed spitzer round, let alone the various steel-jacket or steel-core rounds you see.

[RifleMech]

Kinetic energy is proportional to the mass of the projectile, but the square of its velocity.  This is why muzzle velocity is more important.

Yeah that's a bit beyond me. Plus I don't know the weight of the rounds so I couldn't do the math anyway but we've got the vintage auto-pistol doing 3B/3 while a Gatling is doing 2B/3. That just seems wrong to me. Of course we don't know how vintage is vintage but still, is the C-93 really going to have better penetration than a Gatling Gun from the same time period or a Springfield Rifle?

https://en.wikipedia.org/wiki/Borchardt_C-93
https://en.wikipedia.org/wiki/Gatling_gun
https://en.wikipedia.org/wiki/M1903_Springfield

[CVB]

To make it really confusing, TW charging and throwing rules seem to indicate that (at least kinetic) BT damage against magical armor doesn't depend on energy, but momentum (damage=distance travelled times weight divided by ten).

[RifleMech]

Well, part of the issue is that there is a threshold where putting more kinetic energy into a round actually does less damage in practice. This is a big issue with things like Railguns and why they most likely won't be shooting much faster then ballistic weapons in direct fire cases. The more kinetic energy a projectile has the tougher the target has to be to do any real damage. For example shoot a .50 BMG into a paper target and it makes a hole about 1-1.5in across. Put into some clay and watch it split the clay block. This is because the block of clay is substantial enough to provide resistance to the bullet which allows for kinetic energy to transfer to it from the bullet. It's another reason modern militarys went to smaller lighter rounds because there just wasn't a significant benefit to the extra kinetic energy.

I get all that but how does a .30-06 round fired from Springfield Rifle compare to a 5.56mm round from a M16? How does a round from a Brown Bess compare?

Again a big issue is how vintage is vintage? Reading the wiki entry for the Elephant Gun is the one listed in TW the Nitro Express Rifle?
https://en.wikipedia.org/wiki/Elephant_gun If yes, how would the older versions compare? And can we use that to figure out other similar weapons?

Also when talking about damage in pre-smokeless firearms versus smokeless firearms there is a huge gulf due to changes in bullet manufacture and design to account for the different qualities of a smokeless cartridge.  For example nearly all the various rifles and carbines with pre-1886 centerfire brass were at between 1100 and 1600 fps.  1600fps was considered a very hot load.  Remember pre-smokeless you needed a big bore round in a service rifle to prevent fouling from causing problems even during a single battle.  Lack of velocity meant typically you were firing 10-13mm unjacketed round-nosed lead bullets somewhere between 300-500 grains.  Big soft slow moving bullets that would expand and mushroom like crazy.  For example a family trick when hunting hogs and bears is to put civil-war era style minie balls into shotgun shells with a rifled choke.  I've personally seen those type of rounds remove limbs, punch exit holes the size of a snack plate, and fling chunks of internal organs that weight two or three pounds out the other side of a hog or bear.  The old unjacketed lead blackpowder service rifles had very different terminal ballistics than a modern jacketed spitzer round, let alone the various steel-jacket or steel-core rounds you see.

That is why I would love to have stats for these old weapons. Sure, they may not do as well against an armored target but the softer ones will know they were hit. Plus there's other ammo loads besides the ball.

To make it really confusing, TW charging and throwing rules seem to indicate that (at least kinetic) BT damage against magical armor doesn't depend on energy, but momentum (damage=distance travelled times weight divided by ten).

Yeah. There's that too. I know I'm confused.

[Daryk]

Once you understand the conversion formula, you should be able to make reasonable assumptions about what older weapons stats could be.  Generally:

More AP, more TW damage.
More BD, more TW damage.
Higher Burst value, more TW damage.
Incendiary effects, more TW damage.
Splash damage, more TW damage.
Reload factor can only reduce TW damage, and is one way to easily make older weapons "worse" (see the "Rifle (Makeshift)").

[SlightlyIrritatedCat]

That is why I would love to have stats for these old weapons. Sure, they may not do as well against an armored target but the softer ones will know they were hit. Plus there's other ammo loads besides the ball.

Basically the thing is that those differences get rather more granular than even AToW is meant for and are pretty hard to numerically quantify.  If I were trying to put numbers on old style unjacketed lead ball or hollowpoint I'd reduce AP by one and increase BD by one to account for the fact they do terrible damage to flesh and bone but tend to flatten and fragment on even fairly primitive anti-ballistic armor.  I'm not terribly familiar with AToW, but maybe add non-lethal "bruising" type damage when a character's body armor stops such a round. 

Honestly when it comes to BT I would assume that the old Hague accords are basically a historical curiousity.  We have examples of service rifles firing explosive rounds after all.  So I'd assume that their squad GPMG equivalents are going to be rocking a lot more than standard jacketed ball.  They're probably running belts that are something like (steelcore/hollowpoint/hollowpoint/infra-red tracer) or (hollowpoint/AP/explosive/tracer)

[RifleMech]

Once you understand the conversion formula, you should be able to make reasonable assumptions about what older weapons stats could be.  Generally:

More AP, more TW damage.
More BD, more TW damage.
Higher Burst value, more TW damage.
Incendiary effects, more TW damage.
Splash damage, more TW damage.
Reload factor can only reduce TW damage, and is one way to easily make older weapons "worse" (see the "Rifle (Makeshift)").

It's the Reload Factor I'm getting hung up on. It only makes sense if the guns are emptying their entire payload during the turn. In which case, why bother with bursts?  It's like dropping the vehicle scale machine gun's damage in half when it only has a half a ton of ammo.

The makeshift rifle is also a problem. It's improvised. Not something carefully crafted yet it does more damage than older precision made weapons? I'd swap the AP/BD for the Makeshift Rifle for the Gatling or something.

Basically the thing is that those differences get rather more granular than even AToW is meant for and are pretty hard to numerically quantify.  If I were trying to put numbers on old style unjacketed lead ball or hollowpoint I'd reduce AP by one and increase BD by one to account for the fact they do terrible damage to flesh and bone but tend to flatten and fragment on even fairly primitive anti-ballistic armor.  I'm not terribly familiar with AToW, but maybe add non-lethal "bruising" type damage when a character's body armor stops such a round. 

Honestly when it comes to BT I would assume that the old Hague accords are basically a historical curiousity.  We have examples of service rifles firing explosive rounds after all.  So I'd assume that their squad GPMG equivalents are going to be rocking a lot more than standard jacketed ball.  They're probably running belts that are something like (steelcore/hollowpoint/hollowpoint/infra-red tracer) or (hollowpoint/AP/explosive/tracer)

That's what I would have thought they'd do only "Vintage" weapons get worse as they get older. I think it's because older weapons are vastly underrated because they're old and often have a slower rate of fire. They forget how damaging the weapons are.

We do have various ammo types for weapons in AToW but they're mostly either ignored or averaged together. Both of which I think is wrong.
 

[Daryk]

I don't much like Reload Factor myself (as I've said before).  I would much rather just track ammo.  But it is part of the rule system, at least for now.

[SlightlyIrritatedCat]

I don't much like Reload Factor myself (as I've said before).  I would much rather just track ammo.  But it is part of the rule system, at least for now.

It's honestly why one of my House Rules whenever possible is that small arms just plain don't damage mech scale armor at all.  I split infantry unit attack values so they have an anti-infantry attack using their small arms, and a completely separate mech-scale attack calculated using JUST their heavy weapons.  Because there is a limit to ablativeness beyond which it becomes farcical.

[Daryk]

I think the AP vs. BAR system works fine outside of Reload Factor.  It's not actually that easy for an individual weapon to get to the magical 0.5 of TW damage.  The Auto-Rifle is literally an edge case.

[idea weenie]

I don't much like Reload Factor myself (as I've said before).  I would much rather just track ammo.  But it is part of the rule system, at least for now.

How about making it where weapons do different damage based on shots fired?  But reduce the average damage per bullet when more shots are fired?  This would be for TW Battlemech-scale combat, not for infantry-scale combat.

So using an assault rifle as an example:
you get the most damage per bullet when firing single shot, and the trooper has the lightest ammo load
you get the most damage per turn when firing in full-auto mode, but you have to carry a lot of ammo
3-shot burst provides an average between the two

Using the following numbers as examples (i.e. not actual numbers, just to show the hypothetical difference)
Single shot: does 1 pt of damage per turn (the shooter can take extra time to aim properly)
Triple-shot: does 1.5 damage per turn (some careful aiming, the second and third rounds are likely to miss)
10-round full-auto: 3-4 pts damage per turn (spray & pray, not all rounds will hit, and not all will hit the right spot, but there is still a lot of shots going down range)

Assuming clips store 30 bullets, and you want 60 turns of infantry fire*:
Single shot: carry the assault rifle and 2 clips
Triple shot: carry the assault rifle and 6 clips
10-round full auto: carry the assault rifle and 20 clips

Carrying more clips will mean less available kilogrammage for carrying other stuff (i.e. better body armor, better sensors, infantry TAG, etc)

* turns of infantry fire would be part of the Infantry platoon construction rules, where whichever main weapon is selected for the platoon, you take the value '60', multiply that by the ammunition consumption rate, then divide that by the magazine/clip/battery/flask capacity, round up, and that is how many magazine/clip/battery/flask each infantryman needs to carry.  So if they are armed with pistols having clips carrying 11 shots each, and want to use single-shot, that is 60 * 1 / 11 = 60 / 11 = 6 clips.  If they had wanted to double-tap, that would be 11 clips of ammo.  This value of '60' can be changed to whatever TPTB decide is appropriate.  I figured it was a good value for an infantry unit able to fight 2 battles of 30 turns each, firing each turn.

For weapons that need multiple turns to reload (i.e. muskets), they would technically fire at a slower rate (2-3 rounds per minute), you could set the whole unit as firing at the same time, or take an average for the damage.  So if the musket unit took 3 turns to reload and did .3 damage per musket, then each musket could be treated as doing .1 damage.  Or you could set the musket unit as needing 2 turns of not firing before it can fire again, but each musket would do .3 damage.  Switching freely between the two during a BT-scale battle or tracking individual reload times would not be recommended.  (actual numbers will vary, I just wanted to make the math easy)

[Daryk]

The current conversion actually already does the "less damage per bullet" trick.  A single shot 4P/4BD weapon (with a 1 Reload Factor) does 0.28 TW damage.  The 15-round burst of an Auto-Rifle does 0.52, which is only 0.035 per bullet.  A 3-round burst would be 0.36. and 10 would be 0.44.  My point here is that the damage spread is much narrower than your example.  Going from 1 round to 15 gets you a bit less than twice the damage.

As for basic load vs. combat load, 7 magazines seems to be a typical modern basic load, but combat loads tend to be more (and vary widely).

[RifleMech]

I don't much like Reload Factor myself (as I've said before).  I would much rather just track ammo.  But it is part of the rule system, at least for now.

   I'd rather track ammo.

It's honestly why one of my House Rules whenever possible is that small arms just plain don't damage mech scale armor at all.  I split infantry unit attack values so they have an anti-infantry attack using their small arms, and a completely separate mech-scale attack calculated using JUST their heavy weapons.  Because there is a limit to ablativeness beyond which it becomes farcical.

That sounds good but saying no mech-scale attacks means anything with armor is immune to standard infantry weapons. Including the family car.

How about making it where weapons do different damage based on shots fired?  But reduce the average damage per bullet when more shots are fired?  This would be for TW Battlemech-scale combat, not for infantry-scale combat.

(snip)

Damage should be based on shots fired. The issue is determining shots fired. Unless infantry are going to have more than one attack per turn then we're limited to a single shot or burst per turn. Which is fine.

Tacking ammo is also fine. If you need to reload either don't shoot that turn or roll for a fumble. Successful roll, and your shooting the same turn. Fumble and you can't shoot that turn. Hits and fumbles can be rolled on the cluster chart. Reload turn and the platoon has 4 fumbles. The other 24 troopers keep firing and 16 hit for X damage. The issue with this is tracking ammo. Do we do it per trooper or the whole platoon? Whole platoon is easier. Troopers who fumbled just reload anyway. Better to have a full magazine, than a half empty one. Just in case. But tracking per trooper is possible too. We'd be doing that for support weapons anyway.

And that's for weapons that are easy to reload. I'm totally okay with some weapons needing a turn in between to reload. I don't think muzzle loaders can fire better than 3 rounds a minute anyway. Unless of course they're doubling up or using buck and ball, and other such loads.

And I do think there should be multiple attacks. Physical Weapons shouldn't be hitting at rifle range.

[monbvol]

Reload Factor I can agree as it is currently implemented is not entirely satisfying but I'd take it over actually tracking ammo.

As for small arms not damaging mechs, combat vehicles, and other heavily armored targets I would have no problem with this and it'd be really easy to solve Riflemech's concern about the family car suddenly becoming immune.  Just declare it is not actual armor on it but an abstraction of just how much shooting at it with infantry small arms is needed before it is destroyed.  There are provisions for this idea in AToW itself.

Or compromise and say Commercial Armor, Support Vehicle BAR <=5, and Battlearmor can be damaged by Infantry Small Arms.  This would be largely compliant with the novels I've read and seemingly neatly solve a lot of problems.

[Daryk]

The AP vs. BAR system solves that problem well enough, I think.  To get a single shot powerful enough to do a point of TW damage without resorting to explosive or incendiary effects or burst fire, you need at least 5AP/6BD or 6AP/5BD.  In my head canon, 5AP/5BD is the analog of 0.50 caliber ammunition.  At the very least, it's what the Support Machine Gun shoots.

Thinking about it, if you take 5/5 to be ~12.5mm, then:
5/4 or 4/5 could be ~10mm
4/5 or 5/4 could be ~7.5mm
4/4 could be ~5mm
Below that, you're using something less than rifle amounts of propellant, I think.

Going the other direction:
6/5 or 5/6 could be ~15mm
6/6 could be 20mm
7/6 or 6/7 could be ~25mm
7/7 could be ~30mm
8/7 or 7/8 could be ~35mm
8/8 could ~40mm
9/8 or 8/9 could be ~45mm
9/9 could be ~50mm
10/9 or 9/10 could be ~60mm
and 10/10 could be ~75mm (incidentally, a 30 round burst of this without splash effects gets you 5 points of TW damage; with splash effects, you only need a 25 round burst)

[CVB]

and 10/10 could be ~75mm (incidentally, a 30 round burst of this without splash effects gets you 5 points of TW damage; with splash effects, you only need a 25 round burst)

Interesting. How much TW damage would a single round of this hypothetical 10/10 75mm ammo cause? IIRC, bursts don't do the full amount of damage, right?
(Trying to connect your values with the 5 points from 50kg of AC/5 ammo. A 25 or 30 round burst would result in an awfully light 75mm shell...)

[Daryk]

Single rounds of 10/10 would do 2 points of damage (1.75 rounding up to 2 if no splash effect, 2.25 rounding down with splash).

[CVB]

So ~90% of shots in a burst are wasted...

[Daryk]

I daresay that tracks with reality...

[CVB]

With our real reality? Sure.
With a BT reality of concentrated AC bursts to single locations, rapid fire for double damage, RACs etc., I'm not so sure.

[Daryk]

It all depends on how big you think various A/Cs are.  An AC/2 is technically 10AP/12BD, and doesn't make any mention of how big a burst it uses.

[RifleMech]

Reload Factor I can agree as it is currently implemented is not entirely satisfying but I'd take it over actually tracking ammo.

As for small arms not damaging mechs, combat vehicles, and other heavily armored targets I would have no problem with this and it'd be really easy to solve Riflemech's concern about the family car suddenly becoming immune.  Just declare it is not actual armor on it but an abstraction of just how much shooting at it with infantry small arms is needed before it is destroyed.  There are provisions for this idea in AToW itself.

Or compromise and say Commercial Armor, Support Vehicle BAR <=5, and Battlearmor can be damaged by Infantry Small Arms.  This would be largely compliant with the novels I've read and seemingly neatly solve a lot of problems.

The Reload Factor feels like is a way of tracking ammo. It also feels like it presumes all the rounds are fired per turn. In which case, why track ammo? Which would be fine except the damage is supposed to be per shot or per burst  and it isn't.

I'd be okay with ATOW damage. It does decrease as the BAR goes up. TW gives infantry damage against BAR10. I'm also okay with infantry doing small amounts of damage to mechs and tanks. I think of it as knocking out cameras, view port glass, lights, and such. Plus the number of troopers firing rifles could outnumber a burst from a machine gun so a tiny bit of damage is okay. Although, I did like the rules in TRO:3026 more. Damage with standard infantry weapons was possible but not a sure thing.

[RifleMech]

The AP vs. BAR system solves that problem well enough, I think.  To get a single shot powerful enough to do a point of TW damage without resorting to explosive or incendiary effects or burst fire, you need at least 5AP/6BD or 6AP/5BD.  In my head canon, 5AP/5BD is the analog of 0.50 caliber ammunition.  At the very least, it's what the Support Machine Gun shoots.

Thinking about it, if you take 5/5 to be ~12.5mm, then:
5/4 or 4/5 could be ~10mm
4/5 or 5/4 could be ~7.5mm
4/4 could be ~5mm
Below that, you're using something less than rifle amounts of propellant, I think.

Going the other direction:
6/5 or 5/6 could be ~15mm
6/6 could be 20mm
7/6 or 6/7 could be ~25mm
7/7 could be ~30mm
8/7 or 7/8 could be ~35mm
8/8 could ~40mm
9/8 or 8/9 could be ~45mm
9/9 could be ~50mm
10/9 or 9/10 could be ~60mm
and 10/10 could be ~75mm (incidentally, a 30 round burst of this without splash effects gets you 5 points of TW damage; with splash effects, you only need a 25 round burst)

How would that relate to older weapons? 
A 2 bore Elephant gun is 33.7mm.
A 4 bore Elephant gun is 26.7mm.
More modern ones are .376 in (9.6 mm) - 584-inch (14.8 mm)
Wiki says Elephant Guns were used against light armor in WWII but it didn't say what kind.
Brown Bess is .75/19mm but fires a .69/17.5mm to reduce powder fouling. The muzzle velocity is about the same as the older elephant guns but I know the damage would be less.

So ~90% of shots in a burst are wasted...

But all of Autocannons rounds hit so its a bit inconsistent.

It all depends on how big you think various A/Cs are.  An AC/2 is technically 10AP/12BD, and doesn't make any mention of how big a burst it uses.

The Warrior H7's AC/2 is 30mm and fires 10 round bursts. We can't really go by fluff though. AC/s not only vary in size in the same class but the same size can be in different classes. I just figure they're lower or higher velocity guns.

In game terms though I have AC's firing 2 round bursts, with 4 round rapid fire.

Edit
If using Solaris VII rules though the rate of fire for smaller ACs is a lot higher.

[Daryk]

Older weapons had less efficient propellant, so I'd penalize them on that basis.

[RifleMech]

Older weapons had less efficient propellant, so I'd penalize them on that basis.

I agree. The wiki page for elephant guns says that they went with bigger rounds because the rounds couldn't go faster. So size is helping to compensate for lack of penetration. So if 5B/6 is a modern elephant gun what would the 2 bore 33.7mm elephant gun be? It's just over 3.5 times the size of the smaller 9.6mm modern elephant gun. I don't think the AP should go up but the BD should have a big increase.

It's the size of the rounds that make me think that the vintage Gatling and vintage machine gun and assault rifle are too low. If the M2 .50 cal is a support machine gun and the M1917.30 cal is the portable shouldn't a Gatling gun chambered to use the same .30-06 round do the same damage per round? I can see the older .58 cal round having a lower AP but the BP should be higher. 2B/3 is just wrong. That's less than a crossbow. 

[Daryk]

I suspect TPTB were looking at the original black powder and percussion cap version of the Gatling Gun for their "Vintage" one.  2/3 totally fits for that.   If you want something more advanced, the Vintage Minigun is one row up in the table with 3/4 damage and a 50 burst (for 0.81 TW damage, which rounds up to one point against BAR 10).

[RifleMech]

I suspect TPTB were looking at the original black powder and percussion cap version of the Gatling Gun for their "Vintage" one.  2/3 totally fits for that.   If you want something more advanced, the Vintage Minigun is one row up in the table with 3/4 damage and a 50 burst (for 0.81 TW damage, which rounds up to one point against BAR 10).

That wouldn't surprise me but I think 2/3 is too little. It's more what I would put the Blunderbuss and older firearms at.

This link has a link to a video where a .45 Kentucky Rifle shoots through a steel plate. From the sound of things it was overcharged but it still did it.
https://www.thehighroad.org/index.php?threads/flintlock-weapons-vs-kevlar.663398/  It also talks about the blunt force trauma of being hit with a vest by a .54 maxi-ball and towards the bottom talks about a helicopter getting holes in it from crossbows and muzzle loaders.

[Daryk]

Ian at Forgotten Weapons has a good discussion on 4-Bore weapons here: https://www.youtube.com/watch?v=MDYtxxRU_cY

He specifically mentions they were initially conceived prior to smokeless powder.

[RifleMech]

Ian at Forgotten Weapons has a good discussion on 4-Bore weapons here: https://www.youtube.com/watch?v=MDYtxxRU_cY

He specifically mentions they were initially conceived prior to smokeless powder.

Very cool! Did I understand him right in that they're around 3 times as powerful as a 12 gauge shotgun and that was with a light production load?


So how do we stat these things? I'm going to guess that tripling the Double Barreled Shotgun's 1/6BS damage to 3/18BS is too simple. Still, that's a 1/4 pound of led hitting a target. The .45 Kentucky Rifle also shot through steel plate. So these weapons are still dangerous.

After watching a video of a muzzle loader vs. medieval plate armor, (sorry no link but I'll try to find it,) I think the AP/BP should fall with range for Black Powder Weapons. Up close the .58 round tore right through the armor. At a distance though it left a big dent but didn't penetrate. That .45 Kentucky was also at close range. I'm not sure it'd have done the same at a distance.

[Daryk]

Don't forget "steel plate" can be around BAR 2...

[monbvol]

And typical plate was no more than 2mm, possibly 3mm thick, before smiths started re-thinking how to make it so it could provide at least some protection against these new fangled guns.

There is an Elephant Gun in AToW that might make a good comparison point.

[Daryk]

The Elephant Gun is 5AP/6BD, and if it had 10 shots would do a point of TW damage.  It only has 2 though, so it does much less.

[RifleMech]

Don't forget "steel plate" can be around BAR 2...

Which tells me that black powder weapons should be able to damage it.

And typical plate was no more than 2mm, possibly 3mm thick, before smiths started re-thinking how to make it so it could provide at least some protection against these new fangled guns.

There is an Elephant Gun in AToW that might make a good comparison point.

That's what made me look up Elephant Guns. If the listed AP/BD is for the modern one, we can figure out Black Powder versions and work back to other black powder weapons.

If 5AP/6BD is for the modern Elephant Gun, I think the older BP versions would have a lower AP but a much higher BD. The round doesn't go as fast so lower AP but it's a really big round so higher BD. And then we scale it down to smaller caliber BP weapons.

The Elephant Gun is 5AP/6BD, and if it had 10 shots would do a point of TW damage.  It only has 2 though, so it does much less.

And there's the problem. TW damage is the same for BAR2-10. In AToW damage decreases as BAR goes up.


Just for fun. Civil War Canon vs Car.
https://www.youtube.com/watch?v=AQn2s3zy-kI
Civil War Cannon vs Humvee window.
https://www.youtube.com/watch?v=qYGNP1xyJAU
Thought this was cool
https://www.popularmechanics.com/military/weapons/a24033/syrian-rebels-have-a-mystery-antique-gun/

[Daryk]

Interesting videos, but very different weapons and targets.  The commercial car would have a BAR rating below the armored glass.  The guys that shot the glass also admitted to upping the charge.  That's one of the problems with black powder weapons: the charges are anything but consistent.

All that said, it only takes 8 damage points getting through the armor to kill an average human (with 4 BOD).  That's a completely different yard stick than what it takes to damage tactical armor.  To do that, you have to exploit the rounding inherent in the AP vs. BAR system.  You are correct that when using TW alone, the damage to BAR 2 through BAR 10 is the "same" (except for the critical hit effects), but that's an oversimplification of AP vs. BAR.  I haven't rebuilt the spreadsheet I made that accounted for target BAR yet (I lost the original when the USB drive it was on died).  I'll certainly post it on the forum when I get around to it.

[RifleMech]

Interesting videos, but very different weapons and targets.  The commercial car would have a BAR rating below the armored glass.  The guys that shot the glass also admitted to upping the charge.  That's one of the problems with black powder weapons: the charges are anything but consistent.

All that said, it only takes 8 damage points getting through the armor to kill an average human (with 4 BOD).  That's a completely different yard stick than what it takes to damage tactical armor.  To do that, you have to exploit the rounding inherent in the AP vs. BAR system.  You are correct that when using TW alone, the damage to BAR 2 through BAR 10 is the "same" (except for the critical hit effects), but that's an oversimplification of AP vs. BAR.  I haven't rebuilt the spreadsheet I made that accounted for target BAR yet (I lost the original when the USB drive it was on died).  I'll certainly post it on the forum when I get around to it.

True but they were also firing shot, which isn't all that different from a platoon firing rifles. Either way, the car is still getting shot up. I also think that overcharging is one of the nice things about BP weapons. It's kind of like going from standard to armor-piercing rounds in a way. The AP/BD gets upped a little. It can also be lowered if needed.

I know the likelihood of a civil war penetrating a Mech or Tanks armor is close to nil but BT doesn't rely on penetration. It's about knocking pieces off and if a Mechs physically hitting each other can cause damage, surely a big pierce of led will knock off a small piece of BT armor.




This was fun.
https://www.youtube.com/watch?v=JEKyq7BxTKg
 
https://www.youtube.com/watch?v=3oX2K0aDYnU

I thought this answer was interesting. Most were, "Hell no" type answers. Which I would expect. A few were it might damage the track or drive wheel. Others were yes if it were a siege cannon. This seemed to have some science to it.

Hypothetical Scenarios: Can a 1800s cannon penetrate the armor of a modern main battle tank?
Ian Holloway
, former Principal Lecturer (1997-1999)
Answered 7 months ago · Author has 1.4K answers and 3.3M answer views
It depends on the size of the gun, the type of shot and the tank target.

And there were some very big guns on ships and used as siege pieces.

The effects of smoothbore artillery was extensively tested against armour in the mid 19th century by The Special Committee on Iron. Formed in 1861 by the Secretary of State for War with the concurrence of the Admiralty.

The committee consisted of Captain Dalrymple Hay, R.N. (Chairman), Major Jervois, R.E., Brevet Colonel W. Henderson, R.A., Dr. Percy of the Museum of Geology, W. Fairbairn, Esq., and W. Pole, Esq., with Captain A. Harrison, R.A., as Secretary. this committee sat until 1864 and conducted a large series of investigations and experiments. [1]

The armour tested here would not be as resistant to penetration as rolled homogeneous armour, but it gives us a starting point. RHA is 50–60% more resistant to penetration than iron, at a guess. see [2]

Field Artillery in 1800

[So discounting big guns on ships covered by other answers]

If we are talking about field artillery, so a 12 pounder being the largest gun, that being the largest deployed in the period, then with standard service cast-iron shot the penetration at 50 yards was 1.1- 1.4 inches and about 2 inches with specially treated ammunition -cast iron tending to shatter.

[I have scaled the penetration from larger guns]

This gives us a 12 pounder being able to defeat 12–22 mm of WWII tank armour. This might penetrate an APC today, but not an MBT. It is not enough for the side of a Sherman or a Panther let alone an T-72,. The shot would shatter.

With more modern steel shot, penetration would be about double so at a close range capable of defeating at 1944 medium tank side armour on a good day. Still not enough for most MBTs.

Footnotes

Harrison C A (1866) Results of Experiments with Projectiles of Different Material Against Armour Plate
Development of Warship Armour

[Daryk]

Whoa... I just watched this video about optics: https://www.youtube.com/watch?v=iPrIN0Gie-U

[RifleMech]

Whoa... I just watched this video about optics: https://www.youtube.com/watch?v=iPrIN0Gie-U

Very cool. My worry is that by the time I get it all programed my target has wondered away or worse, it shot me.

[Daryk]

Well, the optics are supposed to work without batteries, so I can only think they would work without programming...

[RifleMech]

I thought it was the scope that just worked without batteries.

[Daryk]

It is, and that still provides a significant advantage.

[RifleMech]

That's cool.

[Daemion]

Deflective and Ablative properties do not work together because they require competing goals.

400 years of metallurgy and new practices derived from high- and low-g environments could yield something new. And, you seem to treat Magic Mech Armor as if it's one thing.  It's quoted as having two layers with different protective properties. 

And, as for your last suggestion - considered it and discarded it for how my mind visualizes things working in the BTu future.

However!  I do see armor densities driving the idea that a 20-toner can have the same outward volume as something more dense and heavier, like a 55- or 70-ton machine. And, a lot of that could be open-air under a facade.  That works great for Mechs, but when you scale that up to ships, it starts to fall apart.

(Aside: Anyway, that's the last I'm going to discuss this. I won't be checking back in on this thread, so, you need not reply to me.  If you feel others can benefit from your knowledge, then, I'm not stopping ya.    )