This build only works because I could replace both [Shotgun Barrage] and [Chilling Reload] with the riven. We're using Viral because with [Saryn] we add corrosive and toxin. This allows the [Sobek] above to get Impact, Puncture, Slash, Viral, Corrosive, and Toxin. For a total of 6 allowing [Galvanized Savvy] to give us an additional 480% base damage, it's a very powerful self priming setup.

It could be further enhanced by running Arcane Avenger for more critical hits, or Arcane Tempo for fire rate.

If you don't have the Riven use [Chilling Reload] in it's place and get fire rate from Arcane Tempo. Alternatively you can just use [Shotgun Barrage] by itself and be careful about your reloads as they will take a while.