suppression brittleness build
 Veteran Build - Warhammer 40k: Darktide 

Alternative ranged weapons and blessings

Vrak Braced Autogun: Fires slower in ADS(aim down sight) position compared to Graia. Graia takes advantage of Onslaught brittleness stack buildup. On hip fire, both weapons operate the same.

Recon lasgun VI: only because it is meta. However, there are better builds out there, and lasguns do not often provide as much suppression (also different set of blessings entirely)

Inspiring barrage for Fire frenzy. If you want more survivability

You honestly won't be going ADS very often. You will be constantly shooting in the vicinity to leverage suppression mechanic. 

The way suppresion works, is that if you shoot in the vicinity of the enemy, you will cause the enemy to duck and cower in fear. Basically a stun/fear mechanic, it doesn't even have to hit and applies to most enemies (except infested and bosses) 

BAG (braced autogun) can quickly get one kill to leverage weapon specialist to output insane melee dps. A combat blade is usable, but fairs far wose compared to rapier. As the rapier has cleave damage. 

You will be weak to snipers (killing them). You can still shoot and suppress them do some degree, better let your team mates handle that. You are responsible for building brittleness stacks where need be.