Auric Ogryn - Rations Earner
 Ogryn Build - Warhammer 40k: Darktide 

Focus on horde clear and supporting your allies to earn those rations.  Use your tools to create space and keep enemies off your squishier friends.  A Vet or Psyker that is regularly stuck in melee is not going to be ventilating shooters and elites or CC-ing crushers, which you very much want them to be doing.  If you are out of coherency with your squishy friends you are gong to be rezzing them. 

The Bull Butcher is dependable and generally always functional.  Spamming lights gets you great wave clear.  Your heavies inflict bleed on single targets.  You also have the uppercut for stagger.   

Use the grenade launcher to take out disablers, snipers, and then gunners that are pinning you down.  It's usually a oneshot but can be a two shot on some stubborn targets.  Its also a great way to get a flamer to stop shooting so you can close with it.  It is also useful for staggering enemies on a downed teammate before you go for the rez.

Never die with a grenade on you.  Its your get out of jail free card if everything goes sideways.  Multiple teammates down?  Nuke.  6 crushers coming at you in a hallway with nowhere to go?  Nuke.  Daemonhost got aggroed?  Nuke.

Use your rush to make space for allies or to get yourself out of a bad position.  You can use it to engage, but be sure you're not leaving yourself in an even worse position.  Those crushers/ragers/maulers will get back up and you can end up body blocked between them and the gunners in their back line.