6mm ARC Uppers

Grid Defense 18" 6mm ARC Upper Receiver - OD Green Finished in OD Green Cerakote Chambered in 6mm ARC 14" Free Float M-Lok Rail 18" 4150 Heavy Profile Barrel - Black Nitride 1:8 Twist Rate .750 Mid Length Gas System 5/8x24 Thread Pitch A2 Flash...