Found out about this the hard way. However, I did email Ralph Arredondo before purchasing one and he replied that it would work. The screws that came with the rib mount doesn't match the holes on the Burris Fast Fire. I sent Ralph a couple of emails on how to resolve this and. To my dissapointment, I got no reply.
My upper is a 16 inch WOA bbl, midlength gas system. I used a VLTOR low profile gas block hidden by a Troy FF HG. It has seen more than 1,000 rounds. No hiccups so far.
As we say here in the Philippines, Mabuhay (long live) to you guys, congratualtions on the victory!
Does this mean that the current state laws (e.g. CA laws on FA restrictions, etc) will be rendered invalid or challenged in court?
here is mine
Barrel - 16inch WOA SS
Gas Block - Vltor Low Profile
Hand Guard - Troy
Compensator - PRI
Lower Parts - Stag
Furniture - Magpul
Upper Receiver - Stag
Optics - Meopta R-1 on Larue Mount
Bipod - Harris on YHM Mount
Trigger - Geissele Automatics DMR Rifle Two Stage