Zsasz | Stimm Supply | Crits | Chem
 Hive Scum Build - Warhammer 40k: Darktide 

So, this is what I have landed on for Stimm Supply build.  Its similar to what others have done, basically spamming Stimm Supply due to cooldown bypassing from Practiced Deployment .  The cooldown is dictated by Stimm Lab/Cartel, hence we only used three points into Tank side to get some extra Toughness DR.  Between Hive City Brawler and Chem Fortified we have about 52% TDR.  Unfortunately you can't get extremely crazy with TDR, because Hive Scum class is more about dodging than damage reduction.  

I've tried a few different options to build more tank/toughness with things like Toxic Renewal but it just didn't seem to work well, so I went back to Nimble and Jittery.

Be aware that if you only using 1 point into Stimm Lab, then you can probably drop Sample Collector.  This is also why our Curios don't have Cooldown reduction, because Stimm Supply is based on the cooldown of your Stimm Lab.  And the only reason we grabbed Maxed Out Chems was to increase our Crit Chance and Damage Reduction.

Weapons

Are entirely up to you, but would lean more into fast/crit type weapons like TacAxe, Shivs, and Combat Knife.  Needle is also an option, however was just annoyed with slow damage build-up and accuracy.. plus no punch through when trying to hit specials in hordes.  Hand Canon is also a good ranged option.

I've tried to use Bone Saw a few times in this setup... but I don't know what it is, Bone Saw just does NOT feel good to use.. and its honestly just seems like a weaker version of TacAxe..