Lasgun Endless Crits
 Veteran Build - Warhammer 40k: Darktide 

The entire purpose of this build is to continually crit as much as possible, and while the damage is very very small, its effective at cutting through entire groups bottle necked. It seems situational, and while big open rooms make this a little harder to utilize to maximum effectiveness, there are more chokepoints than not if your map knowledge is on point. You can swap out Bring it Down! with Superiority Complex if you'd rather have more damage against elites, but I prefer the buff against the unyielding.

Born Leader is extremely effective since you'll have to be with your team anyways, its not a build you can clutch with but being able to handle all gunners and cut through the horde while doing so makes it very flexible. Sword is meant for crowd control but its up to you what you wanna use, as the focus of this build is entirely for the gun. And the extra rending from Rending Strikes helps as well. You don't need suppression immunity from Determined, and can swap those last two points out for things like grenade replenishment or other support based talents, but it helps if you got dreg/scab-gunners keeping you down.

It's only weakness is heavily armored foes, and bosses. It can help, but the focus should be on other gunners if you can help it. Otherwise you're better off using the sword (or your preferred melee weapon) over your gun. Bring preferred relics, but make sure they all carry stamina regen, as Deadshot eats through your stamina quickly in just a few short seconds of firing the gun. The buff remains while ADS, but keep your ears out for disablers or nearby enemies if you plan to keep your stamina close to zero, as dodge is effected by remaining stamina. Having Exhilerating Takedown, Confirmed Kill and Born Leader helps your team more than you think, so long as you're on point.