tom cadia's krak recon: advanced flashlighter
 Veteran Build - Warhammer 40k: Darktide 

My current recon lasgun build.  Video included is 3 auric missions I quickplayed into, 2 successes and 1 failure, mostly to show that even a lower-mid skill/knowledge player can do fine (in auric) with this build so long as you stick with your team. 

Weapons

Recon Lasgun:

-I've stuck with the Mk. XII here but the Mk VIc (the slowest firing one) might also be good with the Onslaught nerf. I haven't tested the Mk VI yet, but I'll change the build if it ends up being measurably better than the Mk XII.

-Infernus is still pretty valuable, although it doesn't feel as great as it used to. You'll notice the DoT more on lighter and difficult to hit enemies (Snipers especially). On Damnation you can pretty much gun down an entire Crusher pack by hipfiring which is hilarious (clip: https://www.youtube.com/watch?v=YCvLueJm3dQ )

-Carapace damage can maybe be swapped out for Maniac damage if you're comfortable with relying entirely on your kraks. In my experience the only tough enemy with Maniac armor is the Mutant (You can easily hipfire Dreg Ragers down), and those pretty much come to you for easy melee. 

Dueling Sword:

-Can absolutely be swapped out for Combat Blade.

-I'd strongly recommend if you bring your own melee to ensure you can kill at least 3 Crushers with it quickly and without dying to chaff. There are going to be situations where your kraks run out and the game tosses a few more Crushers or a pack of Maulers at you. Maulers do go down to the Recon Lasgun but it takes time (meaning you need space to dodge them) and is not viable in melee range.

-You will have melee chaff clear problems since this build doesn't take Trench Fighter Drill or Serrated Blade, and takes Krak Grenades over Shredders. I tend to use the Recon Lasgun to spray chaff swarms and either proc Infernus or just chip HP to help my melee. In general this is one area you're better off relying on the team, so don't run off by yourself.

Curios are standard. If you have your own Curio setup go for it, I think they're mostly personal preference. Just try not to skip out on Combat Ability Regen, it's your most valuable contribution to the team aside from Focus Target.

Talents

Top of Tree: Exhilarating Takedown is fantastic. Volley Adept is QoL. You can take Longshot if you want to try damage greeding, but reload speed will save you when your crits stop rolling and you actually run out of ammo. You can also run Out for Blood/One Motion or even Tactical Reload, although it doesn't synergize as well with Shock Trooper since the timing is somewhat random for ideal reloading, and if you get caught by surprise you lose the benefit. Volley Adept will always work when you need it to however.

Grenades and Aura: The main break with Tanner's build here is that Kraks are good now. The problem is, Shredders are also good, and in general more reliable for staggering Crushers and Bulwarks compared to a Krak which you have to hit (if not on the target then near it). Still, I swapped to Kraks as I was simply not able to Dueling Sword Thrust stack down Crusher packs like I used to. Might be a skill issue, but to make life easier just take Kraks. Grenade Tinkerer is MANDATORY for Kraks. I'm sure you can make it work without but you're far better off just taking Shredder Grenades if you desperately need that talent point for something else. Grenadier is nice but unnecessary. If you really want to take it you either lose all of your ammo economy (Shock Trooper) or 15% damage to Crushers (Superiority Complex) so I'd say it's not worth it for just one extra Krak and a diceroll. 

Survivalist is still your aura.

Unfortunately Kraks require the sacrifice of your most reliable melee skills, Trench Fighter Drill (10% melee attack speed) and Serrated Blade (2 bleed stacks on melee hit). The loss of Serrated Blade is pretty big. It's a great skill and if there was any way to still take it instead of Field Improv I absolutely would. Nothing against Field Improv, you just lose a significant source of melee chaff clear on your Dueling Sword without Serrated Blade. Combat Blade suffers less here, but I took the alternate route of spraying chaff with my Recon Lasgun, since I took Shock Trooper. Without Shock Trooper this may become untenable, depending on your teammates' ammo needs.

Bottom of Tree: Finally we can discuss Shock Trooper. I believe this is a vital and load-bearing talent for this build. To be fully honest the Recon Lasgun does not do enough damage to deal with Auric-level threats. It also has no projectile penetration, so chaff can block you trying to shoot at a Sniper or Gunner line if you're unlucky. Thus, it has to use more ammo on average compared to more meta weapons like the Bolter, Plasmagun etc. Shock Trooper gives you the ammo for this, makes it so you have to reload less, and directly scales with your damage (crit chance). It's still not ideal, and having to take it is a pretty big loss (2 Talent points!) but it gives you so much more slack in terms of ammo pack use and overall DPS. It's strange to say, but Shock Trooper existing is why I run the Recon Lasgun now as an Infantry Autogun main in previous patches. In situations where the IAG would run completely out of ammo, the Recon Lasgun still has around 30%. 

Focus Target is 20% free damage. The other keystones don't do anything for you save a quicker reload with Weapon Specialist.

Feel free to swap Rending Strikes for Competitive Urge or even the Toughness Node. 10% Rending isn't a lot, but I'm not a huge fan of Competitive Urge's mechanics despite the buff being pretty good.

Reciprocity and Desperado are mandatory. Onslaught is worse than it used to be but it's still pretty useful, especially against Maulers. Just be careful around armor until you get used to your ranged TTK. In most cases you'll end up taking out one (maybe two) with headshots before they close to melee range, at which point you just melee them, or more likely your team finishes them off. 

You're still running Shout with the gold toughness node as always.

Build Rationale:

This build started as my update to Tanner Lindberg's starter recon lasgun build, which I had been running keystoneless on both Infantry Autogun and Recon Lasgun. With the release of No Man's Land I'd been noticing that keystoneless wasn't really cutting it anymore (it had probably already fallen off tbh) and I was relying far too much on my melee despite having access to Veteran's ranged buffs, which became VERY apparent in the trench run sections of No Man's Land. So, I ditched the melee "core" of the Veteran and built into Kraks, and it worked out pretty well.