Zealot dagger bleed + crit build
 Zealot Build - Warhammer 40k: Darktide 

  This build heavily depends on a dagger with lacerate trait it won't work if you don't have it.
With this build you can even be more tanky than the Ogryns because you will be triggering Faith Restored (lvl5 feat) constantly making even ragers deal 5 points of toughness damage at max. This build requires you to be aggressive, you always should be fighting to maintain toughness damage reduction. If enemy broke your toughness you need to charge at them or dash away using Chastise The Wicked, do not be afraid of using your career skill it recharges very fast. Don't be afraid of the enemy but don't be too reckless either, you need to balance it out because if you get caught in the open by tons of gunners or hound/trapper they will punish you hard. Fight near cover and put bodies between you and enemy gunners. Be vigiliant for sound cues of trapper and hound.
  You can change your ranged weapon down to your preference however I believe braced autogun or boltgun is the best choice. Braced autogun mk8 is very accurate up until long ranges (+50m) it has very good dps and lots of ammo. It is very versatile because it is very good at horde clearing and elite/specialist killing (except crushers but then very few guns can kill it so it doesn't matter). I hate boltgun due to it is slow readying and reload times and braced autogun can get the job done faster (except bulwarks unless you flank it).
 You should seek health in curios because zealot has low toughness bar (100) it is not a good idea to seek increasing it because effects will be marginal. Health on other hand you have tons of which allows you to make maximum use of Holy Revenant (lvl 20 feat). I recommend corruption resistances because it allows you to Holy Revenant yourself for more hp. You can change one of the curios for wound if you want but I don't recommend it. You can change secondary perks of curios to your preference but extra health is best the thing you can get.

I will provide video and more details on fighting certain enemies soon.