Alpha Shooting Sports 5.56 M-LOK9 Pitchfork Pistol Upper 10.3in Black 103-556MLOK9PF. 3" 5.56 1-7 Cold Hammer Forged MK18 Barrel. Barrel machined from 4150 chrome moly steel and QPQ nitrided for corrosion resistance and long barre life. Carbine Gas...