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. The 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: Your bread and butter is H1->block cancel spam and push-taunts on bigger targets (captains and twins included). No Pushover is not a tax node - it's a critical part of your kit. Block taunt to force grunt shooters to stop shooting and approach you. Shield planting w/ special is also clutch against bosses, elites, and shooters (especially if red-buffed). Take advantage of the minimal startup lag especially when Just Getting Started! and Frenzied Blows  are online.

Mk5 Ripper: I've gushed on this weapon on plenty of my other builds. It's the 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 nor a Vet. Can Opener is a difference maker against captains, twins, and buffed crushers (not so much monstrosities). Mix it in when it's safe.
 

Frag Bomb: For clutches and yolo moments. It will singlehandedly eliminate a heinous ritual as long as there's no goofy hitbox issue with elevation and no ritualists are hiding behind walls or on separate floors.

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 to avoid catastrophe.

Monstrosities: Attention Seeker has no effect on these. Taunt + consistent damage should hold aggro except for Chaos Spawns (it's hard to rip from damage leader for them specifically). 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, push -> push attack to hold aggro when it's safe (know the difference between sword and maul captains), otherwise plant shield. Take special care when Final Toll (red buff at <=50% HP) is active, because shield break won't stun them.

Twins: Magdump their shields -> bayonet -> go apeshit in melee to kill them in 1-2 cycles. Refresh Can Opener as needed. Hold aggro and mind Final Toll like you would for a captain.