Grid Defense Complete Upper Receiver .300 Blackout 7.5 inch Pistol Length 4150 Light HBAR Barrel 1-8 Twist 9 inch Octagon M-LOK Hand Guard Dimpled. 300 Blackout Upper Receiver is an excellent addition to any high-quality AR build. Each of these Grid...
Grid Defense Complete Upper Receiver .300 Blackout 7.5 inch Pistol Length 4150 Light HBAR Barrel 1-8 Twist 9 inch Octagon M-LOK Hand Guard Dimpled. 300 Blackout Upper Receiver is an excellent addition to any high-quality AR build. Each of these Grid...