Basic Sentry's Call build with the Urban MDR and The Devil. Skill Haste should be at 40%. Using Cool Headed with The Devil to get your "Ult." back faster. You need a lot of accuracy with the Devil so, be prepared to sacrifice some damage for accuracy with it. Rolling Stability on the backpack makes the Urban MDR a little more manageable; but, same thing, you need a bit of accuracy for it. 6 Stacks gives an extra 30% damage to that NPC. Some people have calculated more but, I'm no mathematician. I put a bit of Health on Kill for a bit of sustain but, you're welcome to swap that out for something different.
The Devil does have a Handstop mod available. I put an accuracy mod on it with 17% accuracy, stability and reload speed.