Because AC/2 and AC/5 are unlikely to actually penetrate armor . . . the AC/10 and AC/20 IIRC have a much better chance of actually getting that penetrating hit. Shows how long I have not played with AP ammo, I am not sure they even need a +1 TH- I thought their penalties were half weight (rounding down) of ammo count and the mods to the crit roll chart.
Of course with the AC/20 you could theoretically get 3 chances to get a crit- roll snake eyes to a location that has 19 or less armor. Lol, that would be a morale breaker- 20 points of damage to that side torso with ammo, 1 point of damage goes internal . . . BOOM! Mech's ammo gets touched off, the mech literally flies sideways from the three tons of ammo going off in a chain reaction.
The cheering crew would probably not be able to hear the Firestarter running their direction.
I agree the chances for getting a hit with the AC/2 and AC/5 are a smaller than the AC/20. Their -4 and -3 to get crits are a real downer compared to the AC/20's -1. I don't think they need a +1 modifier either but I'd guess it's so the AC/20 wouldn't be that scary.
Rather a penalty without a clear advantage in exchange. I’m totally fine with accepting a drawback if the advantage gained is worth it (see heavy lasers or TSM). AP ammo sometimes rises to that level
It is worth considering if you’re certain about a lot of slow, heavy armor as those crits will probably end up as a lot of crew stunned. That in particular stacks so volume fire from field guns is advantageous. Tying up an alacorn for a couple due to a dazed gunner is a lot of negated potential damage
my calculus also changes when regarding specialty armor listed above but it’s a fringe case with limited applications at the end of the timeline
AP ammo has its applications to be sure. I’d just rather apply something else in most contexts.
I think the targeting mod is to balance the extra chances to crit. Which would be okay except the chances to crit get worse as the cannons get lighter. Couple that with half the ammo and I agree it isn't that balanced and that AP ammo has very limited applications.
Want to say PAC-8 is 12 ammo ... checking now. Nope
goes 10, 20, 40 respectively for the 8, 4, 2 sizes.
Which ends up being 5, 10, and 20 shots of AP ammo. :(
I'm guessing they use the +2,+3,+4 for the AC/10, AC/5, and AC/2?
Hmm, can Battlearmor LB-X autocannons be used as field guns?
You'd think they could use them and Battlearmor Artillery but they're not listed. :'(