Bullgryn Returns - Fitz's H40 Tested Builds
 Ogryn Build - Warhammer 40k: Darktide 

I've recently changed my Thugshot in this build for the GG simply because I feel a little weaker in range with my taunt than I do with bull rush. Bull lets me dodge bullets, contest specialists like flamers, bombers, and trappers, and generally be more mobile than Taunt, which is why the ranged weapon feels less necessary (doubly so if you also run Rock still). GG can't kill a H40 flamer or bomber in one shot.

I've also settled on Power Maul and the Karsolas Pickaxe as my main bull weapons. With Trample and Pulverise, both are equally fun, though both the Mk IV Cleaver and Bully Club are still classics.

If you're running things other than Power Maul + Grenade Gauntlet, you have 3 free points to spend here. Remove 'Slam', 'Ammo Stash' and 'Fire Away' for whatever you might want. I suggest the 'Great Cleaver' subnode on Heavy Hitter, 'Get Stuck In' and 'Too Stubborn to Die' for extra safety.

Feel No Pain is excellent in high Havocs, so you can swap Heavy Hitter for it. Take "Strongest!" and "Toughest!", Pained Outburst is still not worth. Your DPS will suffer, so you might not want to do it on Bullgryn specifically, but it's an option. Remember damage = damage but staying alive also = damage.

As for blitzes, Rock still has good value. Its big benefits are stunning bosses and 1-shotting some maniac specialists (flamers & mutants) regardless of where you hit them, their HP, or modifiers. However, I'm running Frag Bomb more and more because of the Rituals modifier in Havoc and because most classes tend to run regen blitzes, so grenade pick ups go wasted. Bombs Away is usually worse than Frag in most cases.