Dumped everything to FA to take advantage of the damage bonus for every 3000 firearms offered by the set bonus. Running a Covert SRS, as it has the rolls that works. I still want a M700C.The Determined is useful for getting your ultimate back.
Any weapon will do as a secondary. In my case, a classic M44. Unfortunately, not enough stamina for Destructive, but I keep it due to the Predatory. The lack of additional customization might be a limitation in terms of DPS.
This build is great for teamwork during missions with long sight lines/elevated. The main problem for HF is sustain, but if you are careful, you can solo most activities in the game. Life Support lunchbox for revives. Can be replaced with any other healing skill for soloing. During Ambush, I saw 4.6 million crits with headshots (giving you enough stopping power to one-shot most NPCs at full stack)