Optic Ready Carbine is chambered in .223/5.56 comes with a 16? Chrome Moly Vanadium Steel M4 Contour Barrel 1-8 twist , Forged Receivers, A2 Hand Guard, M4 style 6 position Butt Stock, A2 pistol grip, A2 Flash Hider, Trigger and Hammer, Standard Charging Handle, one thirty round magazine. All receivers, charging handles and buffer tubes are 7075 T6.