Lotsa Boolets
 Ogryn Build - Warhammer 40k: Darktide 

"Boolets are NOT food, got it."

--Cronk (Told for the fifth time... today)

The humble Ogryn is extremely synergistic. 
Yes, people think they may be the "weakest" class, IF alone, with all those dogs and nets and such around.
But, no one gets bonuses like an Ogryn. Rather, no one can exploit Veterans and Hive Scum like an Ogryn.

This build works fairly well with most of the classes, but naturally, is bestest with a Veteran or a Hive Scum, nicely with an Arbites or Psyker, and even decent with a Zealot, who knew?

See, the thing is, most of his weaknesses goes away the second he's in coherency, and for some reason the Ogryn's coherency size increase Towering Presence is a mere two talents in.

Hmm...
That plus Born Leader  and Loose Formation and Puppet Master make the coherency radii into massive bubbles don't it? 
HMM...
Doesn't Survivalist and/or Gunslinger Improved (or Anarchist too) sure solves one Ogryn problem with guns, while Seer's Presence helps cut that Point-Blank Barrage 80 seconds down a bunch huh?
HMMM...

Don't get me started with a Hive Scum's Stimm Supply being able to boost it to frankly face melting levels. Ever watch a Daemonhost melt in under ten seconds? 

In short, this build is mostly a general build, but assumes you'll likely get a veteran or a hive scum, plus some of the others.

The Offense (Hint, it's lots of boolets and Point-Blank Barrage ):

Point-Blank Barrage has an eighty second cooldown, yes, but that's manageable with multiple different cooldown reductions applied, including a flat 12% (roughly an eighth or ten seconds flat off) from your Curios, and the Bruiser plunking six seconds off every three. In short, you are usually going to have it when a problem arises.

Now, how it's used is important. 

Fun fact, most people use it when they run out of bullets, but, with Charmed Reload on your gun, your ACTUAL clip is much MUCH bigger than you think. This is why Keep Shooting isn't selected, as you'll often be reloading with some ammo in the gun, when it's quiet. So, the question is when are you hitting that 'F' button?
 

BOSSES: {Plague Ogryn, Beast of Nurgle, Chaos Spawn  & Shieldless Captains and such}
Overwhelming Fire for a few stacks THEN activating Point-Blank Barrage works great, especially with Light 'em Up to get 16 stacks of burn in short order. That plus the guaranteed crits from Burst Limiter Override's lucky bullets which are boosted by Lucky Streak to quite nasty levels.

Plus, your burn stacks, and say a Psyker's soulfire are separate dots, and so is the Hive Scum's Chem Toxin, and so is bleed from any Veteran gun with Puncture on it, if they aren't using a lasgun to shred the armor with Onslaught , well, that's on top of your shooting the boss in the face.

Now, if you're Veteran buddy is using the lasgun with Infernus burn on it, swap Light 'em Up with Hail of Fire to not double dip.
 

SHIELDED BOSSES: {Rinda Karnak Rodin Karnak , Train Boss, et.al. }
Use regular bullets until the shield breaks, THEN pop Point-Blank Barrage and hose 'em. Get a better chunk of them that way.
Just... keep shooting, only stopping to reload, or possibly use some stims to boost yourself further.
 

GUNNERS: Yeah, you hate em', especially as an Ogryn who's a real big target. But, 3 Curios plus Can't Hit Me...Again plus Mobile Emplacement  plus No Hurting Friends! usually, USUALLY, will let you win gunfights with Point-Blank Barrage and three of them, especially with Steady Grip helping with the recharge alongside Bullet Bravado . But, yeah, it's never fun. Shoot em' first or use the shield taunt trick and coax them to turn away from your friends so they can shoot em'.
 

Daemonhost: Yeah, Unload EVERYTHING if one comes a calling. If it's not on you, don't bother to brace, just hose it down from behind, painting the head and back. If it's on you, hopefully you have a Hive Scum with a Stimm Supply to negate the purple.

Still, the mix of Health and Toughness with curios and talents can let you face tank (With dodges) and kill ONE Daemonhost alone. You won't be happy or healthy afterwards, but you can do it. Try not to do it.

LITERALLY EVERYTHING ELSE: Spraying crowds, especially in fog, darkness, the Torrent gas clouds, well, it sets em on fire which makes them easy to see and kill for you and your buddys. That plus the fact your crit rate skyrockets with Massacre means you'll use surprisingly little bullets after the first eight kills. Getting all the Elites with your enhanced coherency means you'll be getting bullets back every five seconds with a Veteran's Survivalist , or, simply just taking pressure off your allies, which means they kill better too.
 

Fun Fact: Point-Blank Barrage will trigger Get Stuck In which makes you and your allies faster, and Unstoppable Momentum makes you faster still, and if you're crazy you can use Roaring Advance to go faster still, and well, be a very fast shooty Ogryn.

The Defense:

Now, this is the variation that uses the shield, mostly to get some tankability without needing to have Loyal Protector . Using the shield and blocking bullets can trigger Attention Seeker  which taunts shooters, and giving crushers and the like a gentle nudge with the shield will turn them around to let your little pals have a breather. 

Plenty of tank guides should be able to give you what you need to know, though do note that lacking Smash 'Em! is compensated by Confident Strike , especially with heavy hits, so you should be getting a fair chunk of toughness without much fuss. 

If you use a Power Maul, swap Attention Seeker with Big Boom or something. That'd be a separate build though.

Later tests with Ceaseless Barrage will be compared to see if you can debuff shooters enough to be offensively defensive, which is what an Ogryn should be doing.
 

The Rock™:

Rocks are good. Rocks save ammo. 

Throw a rock at a charging Mutant: Boom! Problem solved.

Throw a rock at a charging Poxburster: BOOM! Problem also solved.

Pox Hounds can be tricky, but you can peg them if you have it ready when you hear them.

Scab Flamer & Dreg Tox Flamer can be hard to spot with all that fire, but a rock in the middle will invariably get them more times than not.

Plus Rocks grow back, and when you have a Hive Scum, they get happy when they see you have rocks.

Plus, a rock on the back of the head of a Crusher is a great threat generator, and can make them choose you over squishing a little friend. Just sayin'.

Sharing Da Stuff:

Look, normally there's not enough bullets n' bombs to go around. But, this build helps spread stuff out.
 

Bullets: You and the Veteran share em', maybe with an Arbites especially if they got the shotguns out. Psyker don't normally need bullets, and Hive Scum's simply have more in their pockets as needed.

Grenades: You got Rocks, which grow back, Veteran's got grenades which also grow back, and Psyker's got stuff that also grows back. So give em' to the Hive Scum and let either the rockets or chem grenades flow.

STIMS: These are interesting and important. A Concentration Stim can get you to a second barrage if necessary, while Speed Stims will up your fire rate and deal with the classic Ogryn problem of low stamina. And Combat stims are surprisingly useful for a less melee focused Ogryn.

And since the Hive Scum has proven that dots change and grow AFTER chems are applied... actually that makes this need an extra section.

Stimm Supply  and You:

Look, there are two schools of thought: You could stack their rending Fury I n' Fury II with your own sources of rending to bring Carapace armor down faster, swapping the Flak shredding for Carapace. 

Or... 

Get more crits from the Upper right tree, Vultoprene I n' Vultoprene II , and let the Lucky Streak do most of the lifting/killing.

And, the lower left tree, Reflex  with the recoil and reload improvements plus the 50% weapon swap, plus the extra attack speed.

And yeah, Daemonhost's become a LOT less scary when that mean ol' purple isn't a problem.

It's nice. Real nice.

Conclusion:

This is naturally best with teammates who will work with you and know that you're doing this. 

Getting the coherency areas to large sizes makes all sorts of issues smooth out, for them but especially for you.
This build assumes you won't though, and it's still good despite that. 
Your job is to lance a boil, with a bullet. Do that often, and swap to your melee when you need a choke point, or to protect a buddy. 

Eh, you'll figure it out, I'm sure.