Veteran Commando (Infantry Autogun)
 Veteran Build - Warhammer 40k: Darktide 

Weapons

Vraks Mk V Infantry Autogun is a very versatile weapon with very very good handling. It has fairly high DPS, stopping power, fast reload, good ammo economics. You can use it in CQB, or mid range, you have the Torch (tactical light) that is especially useful with the SuperFlaslight mod. This is a fun build, if you enjoy shooting more than melee, it's not competitive at endgame content. I really like to play this on lower difficulties. It is definitely viable, but quiet strained on Damnation, can easily carry lower difficulty games.

Tactics

This is a ranged build, your primary problem solver is the Vraks Mk V Infantry Autogun. Crouch and ADS (Aim Down the Sight) a lot and use short controlled tight bursts! Try to keep out of the fray (Kill Zone), support your team from overwatch positions, flank and shoot enemies in the back for Covert Operative bonus damage! Reload often to trigger Opening Salvo and be ready to take down a squad of specialists!

Use the Catachan Mk III Combat Blade to sprint and deal with melee enemies when you feel like! You can clear Poxwalker hordes with the knife easily enough, if you must, but you can also just leave them there.

Use the Krak Grenade on Elites, Monstrosities, Crushers, Bulwarks!

Use Infiltrate to pick up teammates, reposition and get out of Dodge! Make it a habit to go stealth when you are pressed real hard, get back your bearings, catch your breath, reposition!

Talent options

You can go with Deadshot instead of Precision Strikes.

You can go with Demolition Team instead of Born Leader, this is not a team support build, this is a troubleshooter build.

You can go with Competitive Urge instead of Opening Salvo, if constant reloading annoys you.

You can go with Competitive Urge instead of Covert Operative, if flanking and high-strung CQB is not so much your thing.

You can go with Serrated Blade instead of Covert Operative, if you want to prioritize horde clearing over skullduggery.

You can go with Survivalist instead of Fire Team, if your team is more ammo hungry than average, it doesn't make a huge difference, you need to manage your ammunition carefully.

Ability

Infiltrate with Low Profile gives you very good survivability. This is not exactly a Boss killing build, Arch Heretics with Void Shields can give you trouble, you should weaken Hard targets with your Krak Grenade first! Best to keep annoying enemies off your teammates back or pick them up during boss fights. You can also try to sneak behind them and use your Catachan Mk III Combat Blade with heavy attacks on their skull/spine if there is nothing else to do.