Forward-Momentum Vet
 Veteran Build - Warhammer 40k: Darktide 

This build excels in frontline aggression, easily breaking into any enemy group (save for a Crusher parade on Damnation).

In mixed horde or elite swarm situations, the Agripinaa Braced Autogun, combined with Onslaught and Rending Strikes should put out enough damage to well thin it out. The rifle does poorly at long range but can still stagger and kill Bombers and Snipers (I've found it's best to shoot in small bursts of two or three shots at a time for this). Against groups, go full-auto magdump mode while adjusting your aim with the spray pattern and recoil. Against individual targets at optimal ranges, just fire single shots or short bursts to save bullets. Never use the braced mode, it curbs your movement significantly and, far as I can tell, only reduces your muzzle rise. The rifle's high DPS and suppression makes it incredible against groups of gunners. Be sure to be approaching as you throw bullets downrange so you can switch to melee combat to finish off any gunners/shooters as soon as your mag empties. Always aim for the head to kill much faster and proc Exhilarating Takedown which will combine with Iron Will to keep give yourself a staggering 70% toughness damage reduction when your toughness is almost full. The rifle takes a second to reload and this build has no reload buffs, so reload smartly. Don't sleep on the special attack, it is a push that doesn't cost any stamina. It can buy you time to reload against chaff enemies, stun dogs, push back bursters (inconsistent and risky), and most importantly, combo into an axe swing incredibly.

This is tagged as a melee build for a reason: adequate melee engagement is necessary to save your ammo for mag-dump situations you'll need it for.  Desperado and Precision Strikes on a spec'ed out Antax Mk V Axe does wonders, and keep in mind you get the benefits of Confirmed Kill on melee kills, as well. Use bursts from the rifle to suppress shooters and rush them down, then switch to your axe. The axe can deal with any threat in melee range, though switching to your rifle is a safer way to deal with crushers, if a bit slower. Don't sleep on the special attack, it staggers crushers, maulers and stun locks ragers.

Throw grenades often as you have Demolition Stockpile, one of the best passives in the game. Never pick them up unless no teammate needs them. Try and always have one on you during a monstrosity fight in case you need to stun it out of a grab. Throw them into far groups of ranged enemies to stun their attacks and deal some bleed damage, throw them into overwhelmed teammates to buy them a precious moment of clarity in the horde, and throw them to cover yourself as you help up downed teammates.

Use your ult often, defensively and offensively. It can make a joke out of groups of enemies as you rush them down, it can buy your team time to recompose during a frenetic horde, and it's incredible at rescuing teammates. Combined with your grenades, it can stun a large number of enemies for quite a while.

Competitive Urge is a perk I don't see used very often, if at all, but the benefits are honestly quite massive, and it procs rather often on higher difficulties where your teammates are killing things constantly. You will notice it.

Have fun holding W and shooting everything, but as always, be sure to pay attention to your team composition and teammates and modify your playstyle accordingly to support them!