Light Autocannon 10 and Rotary Autocannon 10.

[Izzy193]

Now the RAC/10 may seem borderline cheesy, but I have taken into consideration on ranges. but since the Rules as written do not let a single cluster go above 40 points of damage, the last 20 points would have to be rolled as it's own cluster. Below is the stats for the LAC and RAC 10.

Light Autocannon/10: Heat: 3 Damage: 10 Weight: 6 tons Crits: 7 Weapon Explodes when hit? Yes Ammo Explodes when Hit? Yes Ammo per ton: 10 Range: 0/3/6/9 Max Number of Shots per turn: 1 Rotary Autocannon/10: Heat: 3 per shot Damage: 10 per shot Weight: 14 tons Crits: 9 Weapon Explodes when hit? Yes Ammo Explodes when Hit? Yes Ammo per ton: 10 Range: 0/3/6/9 Max Number of shots per turn: 6

[Daryk]

I'd kick the LAC up a ton, and remove the "weapon explodes" bit.  That's more in line with the other LACs.

[Speedbump]

Two LAC/5s are lighter than a standard AC/10, so two LAC/10s being lighter than an AC/20 is fine IMO. I'd leave the weight as is.

[I am Belch II]

Will never say no to a RAC-10

[Syzyx]

Didn't Mech Force UK have a 'canon' RAC/10 and RAC/20 back in the day?

[Col Toda]

Make LAC/10 just the breifly intoduced Clan AC made from better metal from Interstellar Operations.. as for Rotary AC 10 and 20 make it for Aerospace only in line with semi capital weapons as they would do 1 or 2 points capital scale no exsposion ammo hit is separate.  Give the rotary 10 short and med and 20 short only .as for tonnage as it jams on a 5 or 6 say 40 percent less than a comparable semi capital weapon.

[Sabelkatten]

I mostly agree with Daryk's comment - remove the "explosive weapon bit" and increase the weight 1 ton. But I'd drop the heat to 2; at 3 heat it's arguably too too weak.

[Daryk]

Dropping the heat makes sense too... The other ACs start at 1, so we don't see that effect.

[theagent]

Seems a bit light (I'd say maybe 7 or 8 tons for the LAC/10) & a bit bulky (maybe 4 slots for the LAC/10), but otherwise seems spot on. 

For the RAC/10, though...based on the conversion of LAC/2 & LAC/5 to the RAC versions, it should have double the weight & triple the slots.  But again, spot on for the heat & damage.

[Demiurge]

I think the secret on making reasonable larger-caliber RACs is just to ignore the previously-established conventions on autocannon calibers.

You can BS some reasoning about how the moment of inertia of the barrel cluster grows too non-linearly to make very large caliber RACs viable or some other plausible-sounding techno-babble... more or less what I did here.

Once you've established that 10 is too high, it's really open season.  Most autocannons do 100 points of damage per ton of ammo, but that's not a hard and fast rule as the -2 class ACs have been doing 90 damage/ton of ammo for literally no reason at all and TPTB have never seen fit to retcon this odd (but irritating) incongruity.

A RAC-4 can have 25 shots per ton and hit exactly 100, a RAC-6 can have 16 and hit 96, a RAC-7 can have 14 and hit 98, a RAC-8 with 12 shots/ton hits 96, and a RAC-9 with 11 shots/ton hits 99.  SRM-6s, AC-2s and several sizes of MML do a worse job of rounding than this so I don't want to hear any complaints about my math here.

On top of that, RACs can't use special ammo so there's no need to worry about coming up with new modifiers for the AP rounds or any other weird rules hitches.

The problem with a RAC-10 is that it's very difficult to differentiate it from an UAC-20.  Previously-established conventions would mean that a RAC-10 is in the neighborhood of size and weight for an UAC-20, and the average expected damage of the 5 shot bursts is a little higher than the UAC-20 on double-tap.  The UAC has bigger hits but fewer of them, the RAC either outranges it and looks holistically better or ends up as a weird gimmick.

I'm not sure why your LAC/10 only reaches to 9 hexes; it feels over-tuned.  You do realize that autocannons suck, right?  You can make pretty much any canon design better by swapping the AC/10 for a PPC and heat sinks and that's without DHS.  You don't need to worry about putting in compromises to avoid making a LAC/10 obsolete the vanilla AC/10; the vanilla AC/10 has sucked since day 1 and any weapon worth taking will obsolete it.  12 hex maximum range is quite reasonable.  Hell, you could sneakily give it the same 15 hex max range and make it just a better AC/10 and you're not going to be turning the game on its head or anything.

[Daryk]

RAC-wise, I think it might be worthwhile to cut the burst down to 3.

[Sir Chaos]

Two LAC/5s are lighter than a standard AC/10, so two LAC/10s being lighter than an AC/20 is fine IMO. I'd leave the weight as is.

I think that´s the wrong comparison to make.

The LAC/2 and LAC/5 are each 2/3-ish the mass of their respective standard AC, so it would make sense for the LAC/10 to be 8 tons.

The RAC/2 and RAC/5 are each 25-ish percent heavier than the standard ACs, so 15 tons for the RAC/10 sounds about right.

[Davion]

Hello, In my timeline a researcher came up with a RAC/10 that only used 3 barrels. That way in the game it only does 30 max Damage if all 3 shots hit so same as RAC/5 but each shot hits harder.

[Charistoph]

Come to think of it.  I remember hearing that the US tried developing a rapid fire 120mm for the Abrams.  It definitely fired fast enough, but the repeated powerful recoil caused the gun to tear the turret off its mount.

Maybe if a RAC/10 (or RAC/20) fires more than 2 Shots, besides the improved chance to Jam, it also forces a PSR akin to the HGR, with a modifier based on the increased chances to jam.

[Sir Chaos]

Come to think of it.  I remember hearing that the US tried developing a rapid fire 120mm for the Abrams.  It definitely fired fast enough, but the repeated powerful recoil caused the gun to tear the turret off its mount.

Maybe if a RAC/10 (or RAC/20) fires more than 2 Shots, besides the improved chance to Jam, it also forces a PSR akin to the HGR, with a modifier based on the increased chances to jam.

I think the most straighforward way to model the effect you describe is to forbid heavy RACs from being mounted in arms or turrets, so the recoil effect cannot tear off said limb or turret.

[Charistoph]

I think the most straighforward way to model the effect you describe is to forbid heavy RACs from being mounted in arms or turrets, so the recoil effect cannot tear off said limb or turret.

That can work as well.  Basically it's a multi-location HGR, too.  Keep in the PSR mods for weight, too.

[Daryk]

I'm liking those ideas! :)

[Cannonshop]

AC/10  ammo count: 10 shots/bursts per ton.   (that is ten shots in single mode, how those shots happen is fluff.)  100 KG of ammunition with each pull of the trigger in single mode.

UAC/10 ammo count:  10 shots/ton x2 so 200 KG per burst of two shots, meaning aside from failures, you can fire it five times before you run out.

RAC/10;  10 shots/ton, but look at your multiplier for a moment.  Double-tap 5 times, like an Ultra, double that, that's two and a half times. (burst of 4), or go all six followed by either four shots, or two double taps.

all this barring jamming.

NOw, back in the day, when we were playing with House Rule designs...I came up with something even MORE absurd.

Behold, te Metalstorm AC/10.  One ton of ammo expended in a single trigger pull at max rate, PSR Plus two to remain standing if you're in a Quad 'mech over 80 tons.  Anything smaller, and it's straight to falling damage *{PSR for half).

May not be mounted on turrets, weapon ONLY comes with one ton of ammo, reloadig procedure involves dismounting the gun and mounting a loaded one.

it gets worse; you take a pilot hit when you fire it.  No save, no piloting check, you take the hit.

Vehicle mounts require a PSR to avoid Crew Stunned result from firing at full max rate.

You can blame John Ringo for this.

[Sir Chaos]

AC/10  ammo count: 10 shots/bursts per ton.   (that is ten shots in single mode, how those shots happen is fluff.)  100 KG of ammunition with each pull of the trigger in single mode.

UAC/10 ammo count:  10 shots/ton x2 so 200 KG per burst of two shots, meaning aside from failures, you can fire it five times before you run out.

RAC/10;  10 shots/ton, but look at your multiplier for a moment.  Double-tap 5 times, like an Ultra, double that, that's two and a half times. (burst of 4), or go all six followed by either four shots, or two double taps.

all this barring jamming.

NOw, back in the day, when we were playing with House Rule designs...I came up with something even MORE absurd.

Behold, te Metalstorm AC/10.  One ton of ammo expended in a single trigger pull at max rate, PSR Plus two to remain standing if you're in a Quad 'mech over 80 tons.  Anything smaller, and it's straight to falling damage *{PSR for half).

May not be mounted on turrets, weapon ONLY comes with one ton of ammo, reloadig procedure involves dismounting the gun and mounting a loaded one.

it gets worse; you take a pilot hit when you fire it.  No save, no piloting check, you take the hit.

Vehicle mounts require a PSR to avoid Crew Stunned result from firing at full max rate.

You can blame John Ringo for this.

On a more modest scale, I think you could model MetalStorm weapons as rocket launchers, except as ballistic instead of missile weapons.

[Cannonshop]

On a more modest scale, I think you could model MetalStorm weapons as rocket launchers, except as ballistic instead of missile weapons.

That kinda defeats the purpose of having something grotesquely absurd.

The entire idea, is you're dumping a ton of ammo (as in a full ton) in ten seconds.  "BRRAAAAP!!!!"  in a big, full-throated rumble...and it's expressly not safe, but it is unsafe in a specific way-that is, it isn't an automatic self destruct on a random table-the tank or 'mech that does it might be stunned unconscious for a round, but if most of that salvo hits, the other guy isn't going to be in any better shape.

which is the whole point of having something that grossly over-the-top.