I need more bullets!
 Veteran Build - Warhammer 40k: Darktide 

We use our Krak Grenade against group of Crushers. Bring it Down!, Superiority Complex and Grenade Tinkerer were picked because they give us the most consistent way to oneshot Havoc 40 Crushers with a single Krak. Columnus Mk VIII Infantry Autogun is your backup against the same enemy if there's not many of them, like 1 or 2.

Columnus Mk VIII Infantry Autogun was picked because it shares the best of both other variants, big magazine, better per shot damage, etc.
But most importantly it has 3 crit chain instead of 2 like Agripinaa Mk I Infantry Autogun, which gives us very consistent crit paired with Deadshot.
While gunning down Crusher, I got only 2 non critical shots.

+2 stam on weapon and +3 stamin on Curio perk allows us to boost Tunnel Vision stamina regen, since it replenishes stamin in percentage, when Deadshot consumes it in points. In addition, we stack x3 +12% stamina regeneration perk and equip Withering Fire. Last one gives us possibility to cleave through 2 smaller enemies (maybe even generic elites) and replenish 20% stamina per weakspot kills with single shot. Otherwise I find myself on zero stam all the time, so for this weapon in particular +6 stamina (including +1 Stamina Boost which we're taking anyway in our talent tree) fills comfortable enough. Just make sure your stamina Curio has 410+ gear score because game shits itself and thinks you have +2 instead cuz it's GS is lower than that value.

Munitorum Mk VII Sapper Shovel is for everything else, and it's special is good enough to deal with high priority single targets like charging Mutant in the middle of a fight.