Mines is my trusty Duke mk44 with rampage, ricochet rounds and range finder, Its just such a great gun for crucible and could easily 3 shot headshot someone, probably one shot if you have rampage X2 or X3, with rampage x1 I was doing 100 damage on a headshot at mid range Edit: although I never tried it out yet, I got trust with outlaw and explosive payload, I'd expect it to be really good though but I never used it cause I already got my Duke 44
Trackless Waste: Wolf Dot W2, Flared Magwell, Tap the Trigger, Snapshot Sights and a Stability Masterwork. Feels snappy and stable with that medium zoom. Also, at least on console, Flared Magwell feels pretty nice to me over Ricochet Rounds in the SMG range. Though, I have seen what a max-range one can do when you play the longer ranges and it appears to be pretty nasty.