I personaly don’t play with bolter because it’s trivializing run. Bolter can hold any threat, so enemies can’t stress you out. Ogryn blob - dead in a few seconds, maulers, ragers - same. Gunners - suppressed or knocked with aoe, waiting to be killed. Well monstrosity can survive just a bit. Unlike with mg12 for example, it is not so good against maulers and scab ragers and useless against melee ogryns (situational for bulwarks), so some enemies can force you to go melee/change position/use nades etc, they can push you to make decisions.
Thats why i think reloading isn’t a thing to nerf. It will ruin bolter for zealot, but if you nerf vet feats it will affect plasma gun. As i already said, bolter it too mobile, same mobility caps as mg12. Maybe ads speed should be lower too.
Bolter
MG12