The snazzy delta ring indicates it's a Knight's Armament FF RAS.
http://quarterbore-com.quarterbore-i.../kacffras.html
The flip-up sights front and rear are PRI and what appears to be an ARMS #40L respectively.
EOTech is the 550 AA model, assuming since he's so hardcore he's probably going to have NVG compatibility.
Surefire is M962, minus the UM07 tailcap for some other Z49 press-button tailcap.
Pistol grip is tan and stock A2 configuration. VFG is tan, KAC pattern.
Couldn't find a pic with the rail cover on the left rail though.
Without pics of the left-hand side of the lower and upper receivers, I can't tell you what the make of the receiver is. Could be Colt, could be KAC. Then again, it could also be Bushmaster, RRA, or even Norinco.