Sprayer
 Veteran Build - Warhammer 40k: Darktide 

The Gameplay Loop

Shoot everything with your Recon Lasgun. Hip fire it most of the time. Zoom in to kill priority targets using Deadshot. Switch to your melee weapon only in dire situations.

Use your Shout (Voice of Command) when crap hits the fan. Throw Kraks when armor or monstrosities show up. And whenever a teammate goes down, prioritize rezzing them! That's it.

Melee Weapon

Use whatever you'd like. Your main goal is shoot everything in the face with your Recon, so your melee weapon is really just an afterthought. I like the Falchion since it slices through hordes and keeps me safe. It can also kill armored targets, although it does take a bit to do so. No matter what I'm attacking, I always charge it up first since it's very weak when it's uncharged.

Gun

The more bullets you fire into enemies, the more you'll crit. The more you crit, the more you'll apply burn stacks through Infernus and save bullets through Shock Trooper. So I use the Mark XII for its insane rate of fire. And in case the team gets swarmed, Dumdum really ups the amount of damage that this Recon can dish out at close range. Headhunter is another great option instead of Dumdum. It might even be the better option. I just like Dumdum since it really helps to clear out the swarm quickly. Try both and see which one you prefer!

Curios

I like using 2 Toughness curios and a Stamina curio. You can swap out the Stamina curio for a Toughness or Health curio if you want. But I like the extra Stamina.

I use 3x Revive Speed because having an ally down for any amount of time is a massive loss to the team. I need them back on their feet ASAP.

I use 3x Combat Ability Regen so that I can Shout more often.

The other 3 options can be whatever you'd like, and I go with 2x Gunner Resist and 1x Bomber Resist.

Top of the Talent Tree

My plan is to hip fire the Recon at my enemies' faces. This means I should be getting a lot of weakspot hits, even when I'm just spraying and praying. For that reason, Exhilarating Takedown is my Toughness talent of choice at the top of the tree. With that being said, Confirmed Kill is also a good choice since you'll always prioritize Specialists and Elites when they show up. Either way, I want Longshot for the extra damage that it puts out at all ranges. It provides more damage at longer ranges, and, it turns out, when you're using Deadshot by aiming down sights, you can hit distant targets pretty easily. The Recon is no Helbore, but it's pretty solid at long range.

Iron Will is amazing with Shout since Shout will get you well above 75% Toughness. Superiority Complex is great. Field Improvisation removes corruption from the team and allows them to restock grenades.

Survivalist is my favorite aura for the team. This is especially true with the Recon since you're a walking bullet hose.

I need a constant supply of Kraks, so I use Demolition Stockpile and Demolition Team. Also, a single Krak might not kill a Crusher, so I use Grenade Tinkerer to really help bring them down with a single Krak.

Shout with Duty and Honour is fantastic. It really keeps your team alive. When a player has gold toughness, they don't take any health damage from bursts of damage, e.g. Poxbursters, Crushers, barrels, etc. And it works great to clear the way so that you can rez a teammate. Only In Death Does Duty End is an option if you want it. But you'll need to drop a talent somewhere to pick it up.

Bottom of the Talent Tree

On the left side, Precision Strikes will give you a huge damage boost when you happen to hit a weakspot (which isn't hard to do when you're constantly unloading bullets into crowds of enemies).

Deadshot is key in this build. When you aim down sights and fire the Recon, your Stamina will drain very quickly. And once your Stamina hits zero, you'll no longer gain the Deadshot bonus. So you need to use this sparingly! When I'm shooting at a horde, I hip fire my gun. But when I need to kill a Specialist or Boss quickly, I zoom in and unload. I keep my eye on my Stamina, and once it gets close to zero, I stop aiming but continue firing. Don't worry! Tunnel Vision and Stamina Regeneration Boost get your Stamina back pretty quickly.

Fully Loaded and Shock Trooper are crucial since they let us keep the bullet hose going. Kill Zone is great, but it turns off if you get hit by a melee attack or block a melee attack. So keep dodging and pushing!

Marksman's Focus is perfect for this build. Whenever you fire into a horde, as long as you're aiming at heads, you're going to get some weakspot kills. You don't even need to aim down sights to get those kills, it'll just happen. And that dramatically increases your damage output. Tunnel Vision replenishes your Toughness and Stamina, so it's absolutely necessary. Long Range Assassin would be great, but you'd have to give up another talent for it. So that's up to you.

In the center section, Tactical Awareness gives us cooldown reduction on our Shout, Rending Strikes helps us deal more damage against "armored" enemies (which means Carapace, Flak, Maniac, and Unyielding), and my favorite Leave No One Behind helps us rez teammates quickly. As I said above, when someone goes down, we lose out on so much: their DPS, their mitigation, their coherency bonuses. I want them back up NOW! This talent does a ton of work and has saved a ton of missions for me. I would honestly swap it out for Shout's modifier Only In Death Does Duty End, but Shout isn't up often enough to rely on it for rezzing teammates.

Reciprocity is all I want on the right side. You'll crit more often as long as you're dodging enemy melee and ranged attacks; and if you're playing correctly, you'll be dodging constantly. Movement is everything in this game. Never stop moving!! With that in mind, an argument can be made for speccing into Duck and Dive. But I'm out of talent points and I feel like I get enough Stamina from Tunnel Vision, so I don't use Duck and Dive. But you might give it a try and see if it allows you to use Deadshot even more.

You'll notice that I'm not using Onslaught. It's pretty strong with this build, but it would take 3 talent points to reach it, and I like the other talents that I've already selected. I'd have to go through Desperado which I don't like for this build since time spent swinging a melee weapon is time spent NOT firing my Recon. And the Toughness Boost doesn't entice me enough. If you really want to spec into Onslaught, you might consider giving up Rending Strikes and Kill Zone, but I just don't know what else to give up. The rest of them are just too good. Up to you.

The Recon Lasgun is a powerful weapon, and this build does a lot of work. But it is a pretty braindead way of playing: Just point gun at bad guys and pull trigger. So if this play style is a little too boring for you, maybe take a look at my other Vet build which alternates between sniping with the Helbore and slashing through enemies, and which requires a higher level of skill and concentration to find success.