The Left 4 Dead Experience
 Veteran Build - Warhammer 40k: Darktide 

It's simple... you just point ya crosshairs on the heretic's head, and shoot 'em. Getting headshots = toughness regen and reload speed, which is beneficial for braced autos since they have sluggish reload speed. Also, to make the most of Kill Zone, try and back away from enemies if you're shooting them. Don't forget to pop Executioner's Stance in order to increase the Agripina's accuracy and proc Marskman for more headshot damage. 

Keep Their Head's Down makes Groaners duck quickly if you fire in their general direction since braced auto have high amount of suppression. Also, Competitive Urge is great with the agripinaa since it deals near max damage for most armor types bar Carapce targets; the extra suppresion from Competitive Urge is nice, too.  

For Curios, extra toughness and gunner resistance is a must for all curios. Sniper reisist is great for at least 2 curios, and the third curio can have whatever you want. 

I choose the Antax Combat axe since its special can stagger a charging mutie. Also, it deals respectable damage against carapce targets. Bromentum is mandatory in order to deal with hordes. Headtaker is also nice for a general damage increase.  

One other thing with this build; it rewards aggression. However, it can be weakish in melee since you do not have any attack speed boosts without a blue stim. In this case, just try to headshot enemies in melee range, and the cleave from the agrinlinaa can hit multiple groaners and poxwalkers.