The Shock Trooper
 Ogryn Build - Warhammer 40k: Darktide 

As described in the Name: You are pushing the boundaries of what a "Typical Ogryn" is known for. 
I will bet money that if you stumbled across this build, it is because you are the few, the bold, the brave, to wield the proud Lorenz Mk V Kickback. You don't shy away from adversity, you are the adversity. You're not some coward, hiding behind your psychers and veterans, but you also don't believe that the versatile Ogryn should be doomed to bare only a boring shield.

Shock Troop, Storm Trooper, "Stoßtrupp", it all means the same thing: Push, and Shatter the enemy's defences as fast as possible, to make way for your lil'uns! 

The secret sauce to your survivability, setting lucky bullet aside (for now), is Lynchpin , Steady Grip , Towering Presence ,& Too Stubborn to Die .
Yes, it is intentional that NO melee-based skills have been picked. This is not an oversight, your bully club will more than easily melt through hordes with your Light attacks paired with Haymaker, or chain your heavies and swipe your way through. There are plenty of overhead attacks, stacked with Thunderous's brittleness, to hold you off, in the rare chance you ACTUALLY ran out of ammunition.

But the only honest ways to run out of ammunition, besides just NOT picking up ammo at all, is if 
1) You are not using Point-Blank Barrage the VERY second it is available, which trust me, with Bruiser paired with Towering Presence, & Maximum Firepower, you can theoretically have another Barrage ready almost as SOON as your FIRST one completes, thanks to the recent buff, reducing the cooldown from 80 to 60s.

2) you are failing to swap between melee and ranged, not taking advantage of the free shotgun shell for every 10 enemies killed. Which, could in theory, be 2, 3, (and rarely) EVEN 4 FREE SHELLS, for the cost of just... swinging your club for a little while.

BESIDES that, you genuinely have very little excuse, besides either negligence or you're carrying a bad team, to run out of ammunition. And if you pace yourself accordingly and time your abilities just right, the very act of you shooting the enemy will keep you virtually invincible. Because the Steady Grip happens IMMEDIATELY once you shoot, maxing out your toughness in literal SECONDS, giving both Smash 'Em! AND The Best Defence a total run for their money. Besides, you STILL gain toughness from swinging your club anyway. I PROMISE you, the amount of toughness from either of those skills is just NOT worth the costly investment of 2 talent points, when you could simply increase your defenses with Too Stubborn to Die, and actually STAY, i repeat this loudly
STAY, with your teammates for the staggering Lynchpin coherency bonus stacked with your Curios' (coherency) Toughness Regeneration Speed. 

Literally just don't get hit for maybe 1 full second, and your toughness will be supplemented handsomly; It stacks up much more than people will give credit for, it is simply because they are selfish players who are so easily-split from their team, that they've never once actually used their coherency to its full potential. Skill issue.

The kickback is your area-denial, your horde-clear, your specialist and elite evaporator, and your very lifeblood. Slide, to dodge initial bullets, activate your ability, and shoot anything that is flashing brightly in your face (the muzzle flashes) as all their attention gets put onto you (I swear this is the case, idk if it actually is, but it genuinely feels like on activation they put their focus on you, just not as buggy as a Tauntgryn). Keep sliding, keep dodging, as you wipe out gunner, after sniper, after mauler, after bullwark, after hound, after flamer, JUST make sure to not spam left click, it's not called Lorenz Mk V Kickback for nothing, and it will become such a waste of good destruction, very quickly, as you're shooting into the ceiling. But time it right, and you can Blender an entire hallway of elites. 
Not even shields stand in your way, with a well-placed shot, the spread is simply too good and will chip the arm of a bullwark, and knock them completely on their ass, allowing your and your teammates to absolutely bully him to death. This stagger is the #1 reason why I'm picking it over anything else, it IS the SHOCK in your troop, literally. Knocking enemies down to the floor gives you and your teammates the breathing room required to push through the enemy lines, and pick off once-was formidable foes, now lying on the floor from the sheer force of your buckshot. 

*sigh* yes, you CAN kill Crushers, and when you max out Blaze Away with the easy-to-trigger Full Bore, relatively-easily as long as you don't get cornered....... but Istg, not every build needs to boil down to "cAn YoU sOlO cRuShErS?" It's literally why this build exists. Your HONEST job, is to wipe out every specialist and elite on the battlefield in under 15 seconds, so your team can wipe out the actual important targets; In other words: lets your team put their bullets where they ACTUALLY belong, not in 50 pox hounds and gunners. 

Make way for the Lil'Uns, Protect the Lil'Uns!

p.s. no, i don't actually have a problem with the shield. I simply find it boring.