Here comes the boom (H40 tested)
 Hive Scum Build - Warhammer 40k: Darktide 

I have tested this build on every Havoc 40 modifier now.. and I have to say it works well for most things you encounter. With all around defense, damage, support, and horde clear, you will be a crutch in order for your team to succeed.

Defense - The Catachan Mk I "Devil's Claw" Sword provides much needed defense when Scab Rager factions appear out of no where on your backline. Backed into a corner? Parry. Chaos Spawn trying to eat your face? Parry. About to take an overhead from a Scab Captain ? You guessed it. The Parry turns your defense into great offense which allows for great survivability on a class that is vulnerable to many enemies.

Damage - Most of the damage output will be coming from your Branx MkIII Dual Autopistols . You can free fire into hordes of armor and not have to worry about running out of ammo with the Pickpocket talent. The pistols do decently well against Ragers, and can even deal with Scab Maulers. Focus on taking out Specialists and Disablers as this will negate unnecessary damage for your team, as well as keep your ammo count up. Let's talk about the best blitz for this build and what this build is centered around, the "Boom Bringer". With the recent buffs, this blitz will take out as much armor as you need it to. There are no worries if 5 Bulwarks, accompanied by 15 Maulers spawn in and corner your team. You need to be conservative with your rockets however, as there are crucial moments when you will need to use them. Let your team know not to steal grenade pickups as this build does not succeed in high difficulty without them. Heinous Rituals.. everybody hates dealing with an additional boss that can wipe out your entire team. Simply aim your rocket directly at the Daemonhost in the center of the ritual, and fire. The talent Pocket Toxin will infect all of the Dreg Ritualists and delete them in seconds. Your team won't even know what happened.

Support - Full Stimm Supply modifiers allow you to negate any corruption your team might receive as well as keep the pace going. The key here is to bring only one Stimm Component so that as soon as the linger effect from Fast Acting Stimms wears off, you are ready to drop another Stimm Supply. This also allows for you to have full stacks of Chemical Dependency at all times. The corruption immunity keeps you and your team healthy from Pox Hound pounces, Beast of Nurgle spit, Daemonhosts, and best of all, Blight corruption (The Blight Spreads). Additionally, the Burst of Energy passive along with Chem Fortified will make you quite tanky, as your toughness will regenerate to 50% upon it being broken; drop a Stimm Supply and you are now back up to 100%. Max out revive speed on your Curios to get those clutch pickups when your teammate gets downed or disabled.

Playstyle - You are mainly going to be sitting in the backline/midline of your team and firing your pistols into everything. Positioning is key as you can't take out Crushers or multiple Maulers easily. Allow your team to deal with them, but don't shy away from shooting at them. You need to be mindful if multiple bosses spawn in as you are going to be holding off the hordes that accompany them. Once your team is safe from the masses, you should be helping break refractor shields and shooting down Captain health and Monstrosities. With great mobility on the Hive Scum, you are able to mitigate most damage by dodging and push attacks.

Thank you for reading, I hope you enjoy the build and have fun most of all.

 The Emperor Protects.