maybe LMGs should be a sort of mismash of automatic weapon type characteristics yet a rival to DMRs and even sniper rifles.
it could have good damage dropoff with less of a deviation between max and min damage, its usual ammunition advantage, and a larger accuracy movement penalty than other classes.
its accuracy formula could work in that it's accurate enough for mid to long range in firing 3 to 5 round bursts but then the accuracy gets moderately poor enough that it doesn't get completely out of control quickly but still non-ideal past whatever would be considered point blank range.
this can be compensated by a slower recoil recovery than other automatic weapons, forcing it to be used at a longer range as a support class although because the recoil doesn't get out of control a player can more or less still "rambo" up to medium range such as when storming a bunker or building, but running and gunning is ineffective.