Havoc 40 Phalanx
 Ogryn Build - Warhammer 40k: Darktide 

For my money this is generally Ogryn's best Havoc build. The shield brings a ton of utility that's hard to pass up. The Mk 5 Ripper is one of the best guns in the game overall, nevermind for Ogryn. Anything else is too slow. Rumbler can be nice, but ammo is an issue in a party where you're asked to do a lot of sniping also. If your team isn't bad they should be able to delete elite packs without much issue anyway.

Hold boss and elite aggro, block taunt shooters, and be a major contributor to boss damage and special sniping.

Slab Shield: H1->block cancel spam is your life blood in addition to push-taunts on bigger targets. Block taunt to force grunt shooters to stop shooting and approach you. Planting w/ special is also clutch against bosses, elites, and shooters (especially if red-buffed). Take advantage of the minimal startup lag. Fatshark changed something where you should be holding boss aggro more reliably.

Mk5 Ripper: I've gushed on this weapon on plenty of my other builds. Most underrated gun the game. Even if you don't outright kill, you'll be staggering/suppressing tons of targets before closing the gap for the kill. Even in H40, a little judiciousness in your ammo usage goes a long way so that you don't need Ammo Stash . Can Opener is a difference maker against bosses. One bayonet tap is enough every 5s.
 

Grenades: For reviving teammates and maybe situations where you just have a ton of stuff up at once (e.g. twins and a captain and an elite pack and a horde).

You should be taking the heat off your teammates constantly. The challenge here is avoiding getting disabled by trappers, dogs, and mutants while doing so. Even getting pounced for a second can be catastrophic.

Monstrosities: Taunt followed by regularly attacking (including Ripper bayonet) and blocking should hold aggro. Plant your shield at the right times. When Chaos Spawns go for the grab, be sure to dodge to the right TOWARDS their arm.

Captains: Their shield isn't worth magdumping on. When shield is up, spam push -> push attack when it's safe to hold aggro, otherwise plant shield. Take special care when Final Toll is the active modifier (red buff at 50% HP). This is important especially for sword captains, since you don't want them suddenly switching targets to a teammate.

Twins: Magdump their shields -> bayonet -> go apeshit in melee to kill them in one cycle. Otherwise, hold aggro like you would a captain.