As I have it, this build is not fully optimized. For primary, I also use Urban MDR with Competent and Intense when the mission requires a little range.
I am doing about 1.4 million damage with BFB. And with Barrett's damage buff activated extra skill power from inventive Tac Stack (30) Talented weapon talents, I do more than 2.7 million damage with BFB.
This build is a little squishy. So stay back, use your turrets for the tac stacks. If playing underground, Showstopper gets you those stacks in 4-6 shots depending on the range. I have 14% HoK overall, that keeps me alive.
What I would change - Rolled about 120 LWM4 and this was the best I got. I would switch to Competent / Talented / Determined or Competent / Talented / Predatory if I had those. Ideal situation would be if I had both. There may be some room for changing some of the major / minor attributes in gear to get more out of this build.
If there are any suggestions, please let me know.