Rumbler+Damage Taunt+BLO is the best Ogyrn build in H40. BLO can be specced to give up to 35% ranged damage and lets the Ogyrn shoot without consuming ammo (highest I’ve went without reloading is four shots in a row). Combine that with taunt specced for more damage and various other damage buffs, things get out of hand really quickly.
Rager/Mauler/Crusher/Bulwark/Special spam? CC the entire horde and clear it at the same time.
Gunner line? Throw a few Rumbler shots at them to CC and clear it quickly. Reapers? Rumbler is coded to one-shot them.
Boss spam? It has high flak and unyielding while clearing out the accompying horde.
Shrapnel blessing is bait, take Shattering Impact or Blaze Away. Or take Blast Zone for hilarity.
Build does suck ammo, but if you’re H40 you should already know how broken this build is and funnel ammo at it.