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 Veteran Build - Warhammer 40k: Darktide 

Whole point of this build is maxing out our Shredder Frag Grenade damage and overall effectiveness, even blessings are picked solely to boost grenades.
If you're having troubles though or playing with not so supportive randos then switch Focused Fire to Overwatch. This way we'll trade a bit of max damage for survivability + more consistent damage buffs.

Infiltrate suppresses all ranged and applies minor stagger to insuppressible enemies (all melee, even Dreg Shotgunner, Scab Shotgunner and Scab Plasma Gunner, they're coded as melee enemies).

You can try playing with Orestes Mk XII Assault Chainaxe with Slaughterer + Opportunist equipped. It's gonna be slow af so I recommend taking Trench Fighter Drill as well. It can decently stagger Crusher with push attack and both blessings will be more consistent than our knife's.

Use dodge slides to maintain Skirmisher stacks time to time (it'll cost you 2 effective dodges, so be careful).

Godwyn-Branx Mk VI Bolt Pistol special attack can trigger Exploit Weakness , but it doesn't benefit additional crit chance from Desperado (while still getting increased finesse from it for whatever reason), so I recommend throwing grenade, going into Infiltrate , then using special attack on closest enemy, Infiltrate will stagger everyone except Ogryns, then you can instantly shoot to proc Execution.
This way you might proc all of those talents + blessings at once: Infiltrate, Close Quarters Killzone, Exploit Weakness and Execution, giving you 85% damage boost out of nowhere :D

Also, underhand grenade throw does not brake Infiltrate, while overhead throw does.