Put it in reverse: ATMs.

[Apocal]

So, normally, you get a thread about a weapon (or weapon type) which asks people lay a case for the weapon. Its strengths and advantages, mitigation of its downsides, ideal use cases, niches, etc. That's cool. I like those threads. But in this one, I'm coming the opposite direction.

Tell me why, assuming a post-3054 Clan force, I shouldn't be using ATMs? Why shouldn't I pull up a Mad Dog D and flex with 72 potential damage just from the ATMs alone? Delete some hapless assault mech with my Turkina D's four ATM12s? Why are SRMs or LRMs or Streaks a better alternative?

[Sabelkatten]

Hmm...

ATM3; ~7 damage (HE); ~3.5 tons.

ERML; 7 damage; 3.5 tons.

ERML is generally better at range 4-5 and 7-15. But of course the ATM can load ER for range 16-27.

The big thing about ATMs, especially the ATM3, is that they get a massive BV rebate. IIRC they have about 55% of the BV they should have for their capability (assuming you carry all ammo variants in decent amounts).

[Col Toda]

Only 2 downsides 1 direct fire only and 2 all Damage  is in 5 point Clusters  . SO an ATM 7 day hits in short range with 4 on the cluster doing 8 points of damage : a 5 point hit and a 3 point hit . A MML 7 does 4 : 2 point hits . An ATM  7 shoot further but an MML can fire indirect with Semi Guided or ARRAD ammo.  I hate the lack of utility  over an Inner Sphere  semi equivalent  .  Because  of a top rack of 12 it is disproportionately affected by AMS . Do I really need to go on ?

[Retry]

The big thing about ATMs, especially the ATM3, is that they get a massive BV rebate. IIRC they have about 55% of the BV they should have for their capability (assuming you carry all ammo variants in decent amounts).

Most of the ATM boats I've seen had their BV fly off into the sun once you start adding ammo.  52 BV a pop on the ATM-12 is fairly reasonable for that fancy super SRM (HE) round, but definitely not for the standard ammo or ER.

[dgorsman]

Infernos and fragmentation rounds.  Thunder LRMs (assuming not following zell against IS/pirate opponents).  Ammo conservation in streak SRMs/LRMs (assuming iATMs are not in play).

Fielding non-omnis in a force of adopted abtakha warriors, which do not already mount ATMs as a Clan design or are IS designs.

[Colt Ward]

Inferno SRMs and IDF LRMs are to me the biggest reasons to still mount those systems on OmniMechs.  Now, IDF is not going to matter as much when the ATM initially comes out but as time goes on- especially against conventional forces which mechwarriors rarely extend zell to- it will be a more important factor.  Unfortunately there are not too many more special ammo reasons to take regular launchers- its not like the Wolf Empire is going to use Semi-G LRMs much . . . though going with ARADs would be interesting.  When restricted to canon configs on Omnis, if I have one slot in my force that does not get ATMs I would rather have SRMs for infernos rather than SRMs- Timber Wolf E, Huntsman H, Adder, B or D, Ice Ferret B rather than a C, and a point of Elementals for example.  Ice Ferret B will let me burn vehicles, BA or put some heat on something that is already pushing its curve.

BUT . . . to me, your garrison standard Clan battlemechs SHOULD have converted to ATMs since it gives them some versatility you get with your Omnis by switching between ammos.  Interesting to note however, the two larger ATM racks CAN clear minefields with HE missiles and the 12 can do it with standard missiles.

[Sabelkatten]

Most of the ATM boats I've seen had their BV fly off into the sun once you start adding ammo.  52 BV a pop on the ATM-12 is fairly reasonable for that fancy super SRM (HE) round, but definitely not for the standard ammo or ER.

Playing (literally!) with BV you should always use the smallest missile racks possible. The BV calculation assumes two tons ammo is good for all weapons, meaning f.ex. MGs get a noticeable extra bonus while ATM12s and HAG/40s really bite it... :P

And for just as bad reasons ATM are assumed to always load standard ammo, so when you load HE you're actually getting a point break!

[Maingunnery]

And for just as bad reasons ATM are assumed to always load standard ammo, so when you load HE you're actually getting a point break!

Incorrect, ATM BV assumes HE ammo as that combo has the highest BV.

[Sabelkatten]

Incorrect, ATM BV assumes HE ammo as that combo has the highest BV.

Hmm... I did the math a couple of years ago and standards matched. Anyway the difference between standard and HE is only a few percent.

But if ATM BV was based on the whole weapon system the ATM3 would have a BV of about 90! a lot more than the 53 it has. But I'd forgotten that ATM ammo for some reason is more expensive than other ammo. Weird. :-\

Anyway, discounting BV ATMs are a pretty average short-range gun, but the added long-range capability means your infighters can meaningfully contribute to skirmishing. Not a bad thing.

Clan LRMs are better than ATMs mid-range and of course have all those nifty special ammo loads and IDF.

Clan SRMs are better critseekers and has infernos.

[Colt Ward]

Clan SRMs are better critseekers

Which is why I wish the nonsense of a 3 pt warhead being split between two locations for HE would get their damage errata'd.

[MoneyLovinOgre4Hire]

ATMs are very ammo-intensive for their launcher sizes.  They lack indirect-fire capability.  The launchers are fairly heavy for Clan missile weapons.  Their lack of alternative munition types inhibits their tactical flexibility and ability to deal with non-mech targets.

[Colt Ward]

The launchers are fairly heavy for Clan missile weapons.

Integral Artemis IV will do that . . .

[Retry]

Integral Artemis IV will do that . . .

I think that's not the reason.  The iATM has STREAK yet weighs exactly the same as the ATM.

[ANS Kamas P81]

Which is why I wish the nonsense of a 3 pt warhead being split between two locations for HE would get their damage errata'd.

Maybe it's just a really large explosion, and enough fragments go outside of the main impact point to do damage to another random part?  Think cinematic, not 100% literal on the rules.

[Colt Ward]

Maybe it's just a really large explosion, and enough fragments go outside of the main impact point to do damage to another random part?  Think cinematic, not 100% literal on the rules.

Sure, I get my 2 HE missiles that hit from a ATM3 can put 5 points of damage on the LA and put that last point on the RA.  But the A4/Copperhead that hits a tagged target does not spread damage to other locations, nor does a SRM split its 2 points between locations.

[Maingunnery]

Personally I think it would have been more logical to give ATM 6pt clusters.

[Sabelkatten]

I still vote for 3-missile hits. 9/6/3 clusters. Makes the missiles feel more different.

[Greatclub]

I still vote for 3-missile hits. 9/6/3 clusters. Makes the missiles feel more different.

that turns them from an armor-peeling weapon to a critseeker. Bit more valuable.

[MoneyLovinOgre4Hire]

It really won't.  HE rounds would do 9 point clusters, standard missiles would do 6, and ER would do 3.  You'd get the same number of clusters either way.  I'm happy with doing that or changing to 6 point damage clusters.

[cray]

Tell me why, assuming a post-3054 Clan force, I shouldn't be using ATMs? Why shouldn't I pull up a Mad Dog D and flex with 72 potential damage just from the ATMs alone? Delete some hapless assault mech with my Turkina D's four ATM12s? Why are SRMs or LRMs or Streaks a better alternative?

Because there are better weapons than ATMs in the Clan arsenal. Clan LRMs:
1. Do equal or better damage than ATMs at 4 to 21 hexes range (and ATMs can't do much damage above range 21)
2. Only need a single ammo type to achieve their damage across all range bands
3. Have indirect fire, while ATMs don't
4. Can use alternative ammo that can do something useful, while ATMs only have different types of damage

If you want gruesome short range damage, Clan SRMs, Streaks, and Small Lasers are the way to go. But other than their short range performance, ATMs are the poor cousins of Clan LRMs.

Inner Sphere MMLs, on the other hand, are everything ATMs tried to be.

[Apocal]

Nothing more embarrassing than forgetting about your own thread.

Because there are better weapons than ATMs in the Clan arsenal. Clan LRMs:
1. Do equal or better damage than ATMs at 4 to 21 hexes range (and ATMs can't do much damage above range 21)

OK, reasons 2-4 make perfect sense, but how do LRMs do better damage than 3/missile? Are you talking damage per tonnage or another balancing metric?

[MoneyLovinOgre4Hire]

Damage per tonnage.  As I said before, ATMs are abnormally heavy for Clan missiles: for the same weight as one ATM 12 you can pick up two LRM 15s.

[Nemesis]

I can only see one reason not to use ATM's, and that's if your bid requires you to use less effective weapons. :P

People can compare the tonnage of various weapons to decide which is the most efficient to cram the maximum throw weight on a mech, but that's not how most games are set up. We haven't built forces by weight since the 80's, we use BV.

ATM's are one of the most BV efficient weapons in the game. All you need to bring some sweet, sweet HE love to the nearest screaming victim is a platform with some decent speed or jump jets, or both (I like the Conjurer 5 and Grendel E).

I guess you could say that ammo dependency or potential explosions are a downside, in which case you could choose to take HML with a TC instead. That's another hard hitting gun with an incredbly low BV/damage ratio in the same range brackets.

[MoneyLovinOgre4Hire]

ATMs are "efficient" in BV only because they're inefficient in weight.

[Colt Ward]

Damage per tonnage.  As I said before, ATMs are abnormally heavy for Clan missiles: for the same weight as one ATM 12 you can pick up two LRM 15s.

Does that include the Artemis IV for each LRM 15? . . . ATM12 is 7t, the pair of LRM15s w/Artemis IV is 9t . . . so . . . and 1 crit less overall.

[Nemesis]

ATMs are "efficient" in BV only because they're inefficient in weight.

Efficiency has got nothing to do with weight, and hasn't since BV1 was invented. If something is so heavy that you can pack less of them on a mech, then thanks to BV you'll wind up bringing more mechs or heavier ones.

You're making the same argument IS players have made for 30 years that Clan LRM's are broken because they weigh half as much. Sure, that means you can carry twice as many, but it means your mech will cost twice as much. Clan or IS, you still bring the same number of launchers to the table for the same BV.

Assuming average cluster rolls, and including the BV for 1 ton of HE ammo, all ATM's cost 9.1 BV per point of damage. LRM's with ammo are about 19.5 BV per damage (18.9 with Artemis), and an ERML is 15.4. Yes they both have range advantages, but that can be dealt with by mounting the ATM's on a platform with mobility, and an ATM with normal ammo is just 13.7, still less than the ERML for the same range. The only weapons cheaper in BV/dmg then an ATM(HE) are ERSL and the various range 3 weapons.

But getting back on topic, the question was why not use an ATM. The answer is there's really not that many reasons not to. Yes, I'm a fan of them. Mounted on fast medium mechs they suit my preferred cavalry playstyle quite well, and they also pass the MathTech test.

[MoneyLovinOgre4Hire]

I'm not saying that Clan LRMs are broken, though.  I'm saying that for their tonnage, which is something mechs have to deal with regardless of rules edition because equipment tonnage is a thing and mechs have finite amounts they can devote to it, Clan LRMs are better than ATMs.  This is not mysterious, this is something that's been known since ATMs were added to the game.

BV does not determine a mech's efficiency.  Efficiency is how effective the mech is at its role for its BV.  Sure, ATM 12s can do big damage with HE rounds.  But you've got to be at 6 hexes or less to effectively pull this off most of the time.  Even with a Fire Falcon E or a Hellhound 5 has trouble pulling this off at will without exposing itself to a lot of return fire.  At six hexes you're inside the short range bracket of a lot of long-range weapons, meaning that your opponent is likely to have equal or better odds of hitting you than you do of hitting them.  Things get even worse with pulse lasers.  Sure, your ATM pod has lower BV than your opponents LRM pod.  But that's because you're rushing to try and get to six hexes while he's hitting you at 14.

[Greatclub]

It really won't.  HE rounds would do 9 point clusters, standard missiles would do 6, and ER would do 3.  You'd get the same number of clusters either way.  I'm happy with doing that or changing to 6 point damage clusters.

OK, I misunderstood. And now I have a problem with the depth of hole the HE would generate - that will get through the back of almost any medium on one cluster.

[Apocal]

Damage per tonnage.  As I said before, ATMs are abnormally heavy for Clan missiles: for the same weight as one ATM 12 you can pick up two LRM 15s.

Ah, got it. Yeah, I was stuck on doing 1 for 1 comparison of the launchers themselves -- there the ATM doesn't look bad at all.

[Colt Ward]

See above, you STILL cannot get 2 comparable LRM15s- IE they have Artemis IV- for the weight of a ATM12.  The ATM12 gets you 2 tons lighter and at least a crit less.

ATM wins . . . 27-22 hexes damage, 18-15 hexes chance to hit, probably damage 9 hexes & under, definitely damage 3-1 hexes.

One of the things we say MRMs are good at also applies to ATMs, and that is urban reorganization . . . while at 15 hexes, the ATM12 can clear mines.  The ATM9 can clear at 9 hexes.