Vet no more ! ( Havoc 40 )
 Veteran Build - Warhammer 40k: Darktide 

Build alternatives :

1. The Atrox Mk IV Tactical Axe is in my opinion the best of the 3 variants in our situation, heavy critical weakspot attacks being devastating and easy to use, while the special give you enough stagger to break off Havoc 40 Scab Rager mid attack. But, you could technically try the other two variants even if to a lesser efficiency. The Atrox Mk II Tactical Axe is a better weapon to spam light attacks with, but the base damage reduction of the weapon doesn't allow for better value than the original mark, on top of that, the special hit doesn't give as much stagger as the other marks, and even with basically a guaranteed weakspot hit, does not show enough damage to be considered here. The Atrox Mk VII Tactical Axe is the in between the 2 other marks, better light attack and worse heavies than the MK IV and better heavy and special but worse light than the Mk II, out of all 3, i wouldn't recommand the Atrox Mk VII Tactical Axe the most. 
2. You could very obviously use better meta weapons such as the Achlys Mk VI Power Sword but that isn't trully the point of any build i make. You could also be using the Munitorum Mk III Shock Maul or the Aridin Mk I Power Falchion but as both were used in recent veteran builds of my own creation, i didn't used them. the choice is yours to try out !
3. Weapons Specialist is a unique perk in the sense that the crit chance given by it is only applied to the first shot fired. This specificity significantly reduce the range weapons usable with it to maximize it's value. The following weapons can maximise this aspect : M35 Magnacore Mk II Plasma Gun, Godwyn-Branx Mk IV Bolt Pistol , Crucis Mk XI Double-Barrelled Shotgun and finally the Zarona Mk IIa Quickdraw Stub Revolver. Now, the M35 Magnacore Mk II Plasma Gun isn't of much interest to me as i avoid meta as much as i can but will be extremely strong ( obviously ) if used. The Godwyn-Branx Mk IV Bolt Pistol are a good choice but could be used in other builds better. The Crucis Mk XI Double-Barrelled Shotgun on a veteran suffer from the fate of not having another class dedicated to long range fighting making it unsuitable. The Agripinaa Mk XIV Quickdraw Stub Revolver suffer from a similar fate to the Crucis Mk XI Double-Barrelled Shotgun. Which leave the Zarona Mk IIa Quickdraw Stub Revolver, more seen from Zealots, this weapon is an extremely strong pick for the veteran, even at the highest level of play. But please, do try yourself the other options listed and come to your own conclusions !
4. You could replace the 5% crit chance on the Zarona Mk IIa Quickdraw Stub Revolver for 10% crit damage, both are great and it is up to you to find your preference.
5. As we aren't using Deadshot, we do not need any Stamina curio, leaving us with the 3 standard toughness curio for our old range fighter. BUT considering the more unusual melee focus of this veteran build, I sacrificed 4% combat ability regeneration for 5% health ( which i will explain later ). Yet, if you desire more uptime for your Voice of Command, then by all means, go back to 3 curio equiped with combat ability regeneration.
6. Your only wide horde clear option is in your Shredder Frag Grenade. If you do prefer Krak Grenade to damage bosses easier and sustain tougher enemies spam easier, then keep in mind that this build does not posses any other form of high horde clear, which in turn will make you struggle when surrounded.
7. We do have a few talent tree options here : You could swap Trench Fighter Drill for Field Improvisation if you desire to regenerate grenades in a pinch and heal corruption, sacrificing a better melee output while doing so. Invigorated and Duck and Dive both have a 3 second cooldown, one boosting your total stamina and reducing your stamina cost, while the other one regenerating large ammount of stamina. Toughness Boost ( 25 at the lower right tree ) can be swapped for Agile Engagement, losing survivability for the sake of better damage every swap ( i personally find it unecessary as it doesn't change your melee nor range breakpoints in any meaningfull way ). 

Strength :

• Spamming melee heavy weakspot attack will kill every enemy in the game. Onslaught allowing you to kill even more armored enemies ( Scab Mauler, Crusher, Scab Captain and monstrosities ) much easier, be it from the direct damage of every hit, or trough the damage boost given to the bleed ( applied by Serrated Blade ) due to the armor reduction of the target. To a lesser degree, you can handle horde trough melee, but that is a slow process. The Atrox Mk IV Tactical Axe is a weapon that mainly works around critical hits and attack speed, those stats being enchanced largly here with Trench Fighter Drill, Reciprocity, Desperado and Exploit Weakness.
• Weapons Specialist guarantee a crit from your next Zarona Mk IIa Quickdraw Stub Revolver shot, every time you kill 3 enemies in melee. Combined with One Motion to swap easier and Hand-Cannon, it'll allow you to kill every armored enemies ( and basically everything apart from bosses ) with one shot. Keep in mind, that due to Point Blank ( 20% crit on melee kill for the next 2.5s ), 5% crit chance on the revolver and Reciprocity ( up to 25% crit chances on dodge ), even one melee kill ( which of course will activate 33% crit chance from Weapons Specialist ) will bring you to a total of 83% crit chance, allowing you to kill an enemy with melee and quick swap to damage ( or kill ) a priority target near you. Finally, Always Prepared will bring back a bullet in your magazine for each melee kill, allowing you to chain until you do not have ammo left. 
• Speaking of ammo, the basically only Aura of the Veteran, Survivalist, will maintain you and your team ammo economy high troughout the game.
• Shredder Frag Grenade bring you the amazing horde clear that is otherwise missing from your weaponry. Sustained with Grenadier, Demolition Stockpile and Demolition Team, it'll allow you to spam them and still not impact the grenade economy of your team. Each grenade being buffed by Grenade Tinkerer, you end up with a devastating tool in your arsenal. ( You can even deal with hordes of armored enemies with those grendades and finish of the remaining unhealthy Crusher with your melee )
• Confirmed Kill, Close Order Drill, Iron Will, Catch a Breath, Toughness Boost and On Your Toes will mantain your Toughness lever high and renererating at all times, while Voice of Command + Duty and Honour will give you and your team the sweet golden toughness. Making you very hard to kill. Voice of Command coming back quicker due to the 8% combat ability regeneration from your curios and Tactical Awareness.
• The 5% health increase from your curio make you go from 98 health to 106 ( Havoc 40 values ). This matter, in the sense that Poxburster do 100 health damage in there inner explosion radius, which if you are ever exposed to such things will make you go out alive with 6 hp. Considering that you are a melee focused build, this can be a life changing attribute. 
• You are a melee fighter that can without issue sustain range combat. Giving your team a form of flexibility in it's gameplay.

Weakness :

• You are not using Fully Loaded nor are you using a Las weapon with Shock Trooper making your ammo count more limited than usual. Each bullet being more important the the one before and your need for ammo directly impacting your team ammo economy. Do not get me wrong, you very much can shoot a lot, but do not expect to do the same as you would with an Accatran Mk VIc Recon Lasgun.
• Your fight against bosses are slow. You do a significant ammount of damage trough direct hits and bleeds, but you do not damage the shield of Scab Captain and Twins quickly nor can you kill a monstrosity with 3 Krak Grenade and a few weakspot hits. If you do not have a dedicated boss killer or holder in your team, you might struggle in tighter situation in which those bosses spawn.
• Some unluckiness with crits in tight situations, specifically when Crusher surrounds you can make your survival a more complicated and skillfull issue to solve. 

Conclusion :

Unlike most of the builds i created so far, this wasn't a direct clean idea that i could use right away and fine tune quickly. It was a slow process of multiple conflicting ideas of which this build came out of. 
As you may know ( if you read other builds of mine ), i try my best to come up with valuable strong builds for the highest level of play ( Havoc 40 ) that are outside of the meta and by the definition of it, usable in any other lower level of play. This build i consider a success in that regard, even with the inevitable Voice of Command and Survivalist, the otherwise often seen Zarona Mk IIa Quickdraw Stub Revolver, the occasion of which a melee Veteran of high horde clear using a Zarona Mk IIa Quickdraw Stub Revolver at the highest level of play is rare if not basically unknown. 

As i was writing it down, i realised how few weakness i actually found in this setup.

A very strong build, a very fun and nervous build that cut out from the usual Veteran gameplay and grow closer to a Zealot or an Arbites while keeping the uniqueness of the class. One that may fit even people uncomfortable to this class in higher level of play. 

I strongly suggest understanding the Spicy Rythm that this build gives as you give it a go and once you're try and hopefully fun is done ( or ongoing ! ) to come to me and speak of your experience using this beauty ! ( Giselle5957 on discord )