Street Sweeper
 Hive Scum Build - Warhammer 40k: Darktide 

The double-barreled shotgun has been mostly forgotten since it was released, but I finally have a build for it that's not only effective, but surprisingly fun to play. If total number of heretics slain is what you're looking for, then look no further. Now then, let us cleanse these foul streets!

Ranged

Crucis Mk XI Double-Barreled Shotgun: Dust that bad boy off and get ready to embrace your inner Doomguy. Both modes do amazing damage AND stagger at close-range. While the gun's carapace armor damage might not be amazing, its stagger is. Hit a Crusher in the face with both barrels will knock him on his ass. The dump stat is Mobility because even at 60% you still get max amount of dodges (4). You'll be tempted to just go for body shots but aim for weak-spots when hip-firing.

Note: Firing from the hip does have a bit of spread but not the crazy amount of spread you might be used to from every other video game shotgun in existence. Getting the most out of this gun will require a bit of aim. I remember having to go through a bit of adjustment, thanks to habits from other games, to get used to this. On the other hand, alt-firing with both barrels will give you a much wider spread. 

• Perks: For max horde clear, I go for +25% damage to Flak and Unarmed.
• Blessings: You'll be reloading constantly, and the base reload speed is pretty bad. That said, I go for Speedload and Both Barrels, although Deathspitter (+6.5% Strength on close range kill, up to 5 stacks) is a worthy alternative. If you find yourself using the alt-fire a lot, replace Speedload with Scattershot (and consider ditching the Sticky Hands talent) for more crits.

Melee

Crowbar: I really don't find myself needing to switch to melee that often due to how good the shotgun is, but when you're completely swarmed, the crowbar is good due to it's stagger potential and sweeping push attack. Also the alt mode is brutal as all get out. It can chain stagger crushers and will save you in crisis moments.

• Perks: +2 Stamina for more push attacks and +25% Carapace Damage for alt-fire attacks on Crushers.
• Blessings: Because the crowbar has no decent stagger blessings (for shame, Fatshark), I go for both the push attack blessings (Take a Swing and Bash) but honestly, it's your choice here.

Key Talents

Ammo Jack: Effectively turns the double-barreled shotgun into a triple-barreled shotgun. You'd be surprised at how much this simple change does for this weapon. The Veteran has the same talent available, but he doesn't have Desperado.

Sticky Hands: -30% spread when firing from the hip does wonders for this gun since you're not going to be using the braced fire that often. And when you do need to alt-fire, you'll have an extra round for cleanup. NOTE: If you like using alt-fire a lot, and who could blame you, then consider replacing this with something else. The double-barrel shot hits wide and does great stagger, so the reduced spread is actually detrimental in this regard.

Pickpocket: Still a must have talent for any Hive Scum build focused on ranged, despite the nerf.

Blitz

Boom Bringer: aka the Carapace Clearer. Thanks to a recent patch, Crushers aren't as common as they used to be, meaning you can get away with just two rockets, instead of having to get the Extra Pouches talent for the additional rocket.

Ability

Enhanced Desperado: This ability has incredibly synergy with the double-barreled shotgun. Sprinting costs no stamina and is 20% faster which allows you to easily close the distance with gunners or ranged heretics. Ammo is free as well, as long as you have at least three round in your reserve. 

• Ability Modifier - Pick Your Targets: More rending and more damage. No reason not to get this.
• Ability Modifier - Focused Resolve: Synergizes with other ability cooldown perks but only slightly due to the 5 second cap (Desperado has a 45 second cooldown).

Aura

Anarchist: 5% crit for you and the team is my pick. With Desperado and Pickpocket, ammo shouldn't be too difficult to maintain, but if you're having difficulties doing so, then go for Gunslinger Improved.

Keystone

Vulture's Mark: You'll be focusing on horde clearing but it's not like you won't be killing every elite/specialist you come across either, so why not get some extra damage, crit, and movement speed out of it?

• Keystone Modifier - Vulture's Push: The stagger is hardly noticeable. Do not get.
• Keystone Modifier - Vulture's Dodge: Sometimes I get this and sometimes I don't. Worth it if you're having issues staying alive.
• Keystone Modifier - Patient Hunter: Given the short range of the shotgun, and the fact that you'll be focusing on hordes, keeping the Vulture's Mark buff up can be challenging at times. This one helps with that.

Stimm Lab

• Cooldown reduction: It frees up Desperado for use as much as possible.
• Damage and Rending or Crit: Both are good.

Mods

For PC users, I recommend the following mods.

Healthbars (with all enemies enabled): Highly recommended. Because seeing 10 heretic healthbars go from full to empty on a single shot is a wonderful thing. It also makes you incredibly efficient at horde-clearing, as you'll know when they're dead.

Keystone Blitz Bars: Gives a good visual for current Vulture's Mark stacks. I had to also get the following mod for it to display correctly.

Custom HUD: Allows movement of all HUD elements. Has great integration with other UI mods.

Guarantee Ability Activation

Guarantee Special Action

Guarantee Weapon Swap

Scoreboard w/ Ovenproof's patch