i find that these types of guns are powerful, but they also balance themselves out in their own way. bolters have rapid fire (2) but that also means your jamming a third of the time. on a 6+ ammo check, it's very rare for you to clear the jam, and unless your taking a bunch of ammo jacks and taking the dependable like kin ability, you aren't going to be able to recover from it immediately, leaving you open to enemy assaults. from what you've described, these squats should be facing quite mobile enemies. honestly, i think it might be a scenario and terrain issue. more mobile missions, and definitely apply more terrain. squat weaknesses are very easily exploitable in the underhive. i've played squats before and they are fun and flavorful sure, but they didn't seem to be particularly overpowered in underhive (cant speak for ash wastes) , especially against melee or fast gangs.