There's a nasty bug in that if you fire a burst at someone with a corpse in between, all but one shot hit the corpse. Every time. If that could be fixed, big guns would be a lot more useful. As it is, the miniguns/machine guns are only good for softening up crowds from a distance. Flamers' short range and heavy fuel limit their usefulness. The only time it's really worth lugging one around is clearing out the wanamingo min. Rockets do lots of damage, even to power armor - more variable, but on average explosive rockets are about the same as gauss and pulse rifles, and AP rockets do significantly more damage. Too heavy to carry many around, though, unless you have some NPCs. Just remember not to give Marcus a launcher as well.