Advanced Armament Corp. (AAC) MPW A3 AR-15 Upper Receiver Assembly - 5.56 NATO, 16" Barrel, KAC URX 3.1 Quad Rail
This Advanced Armament Corp. (AAC) MPW A3 upper receiver is built around a 16" 5.56x45 NATO barrel with 1:7 twist and a Knights Armament URX 3.1 quad rail (marked "URX3.1 13.5"). Up front it is fitted with an AAC 51T Blackout flash hider.
A slick nickel boron coated bolt carrier group is included. Also included is a Magpul MOE SL-S stock in the original box.