USF AT gun has this ability and it doesn't have any drawback to it.
Plus, what good is a vet ability, if the thing can't get vet, because it can't penetrate anything bigger then halftruck.
Yeah, but the core concept is fine, just the numbers are no good. 30% more pen (that's what it was, right?) for 30 muni obviously isn't cutting it for 57mm, so the M-42 would obviously need a lot more. Could also make the M-42's only have a cooldown and no cost, because even more so than the 57mm it's fucking useless without the ability at most stages of the game.
Either way, I think the M-42's initial value may be arguable, but its scaling is so trash that Oscar's a close friend of it.