Havoc 40 certified slab tankgryn
 Ogryn Build - Warhammer 40k: Darktide 

I had a lot of success with this build.

You use a lot of pushes. Standard horde clear combo is heavy 1, block reset, heavy 1 loop while occassionaly pushing for stagger and taunt.

If you have wave of dogs you can spam push, taunt some of them through pushes and in general give your flame psyker enough time to kill them as you spam 10-15 pushes in a row. Makes dog waves trivial.

Against armor you spam heavy 1, push, heavy 1 loop while trying to hit crusher/mauler heads. Remember to dodge backwards here when you're going into overhead charging crusher. You have high chance of staggering them out but you don't wanna get hit by the occassional struggler.

Use your shield special sporadically but remember you have it! It's not that good against bosses but it's great for pushing into gunner/sniper infested areas where you pull aggro on yourself and plant your shield while your team is free to deal with these.

For bosses you mostly want to use horde clear loop while pushing every 9 seconds for the free taunt up and taunting in order to stagger out of overheads/melee tantrums.

You are very tanky. I mean that! You are not in the team to deal damage. You are there for your stagger and ability to let other teammates deal their damage easier and get into areas which would otherwise hurt them.

Use your rocks and stubber in order to snipe specials and muties whenever you're free to do so. You should reserve your rocks mainly for muties and potentially for back hitting beast of nurgle when it snatches somebody.