Action: Semi Auto - Caliber: 5.56 mm NATO - Action: Gas Operated Semi Auto - Capacity: 30+1 Rounds - Barrel Length: 16 - Front Sight: Adj. A2 Post - Rear Sight: Folding Magpul MBUS - Overall Length: 32 - 35 - Grip: Polymer - Weight: 6.45 lbs. - Barrel Material: 4140 Steel - Upper Material: 7075 T6 Lower - Material: Aluminum - Finish: Matte Black - Forged Integral Trigger Guard - Armornite Finish (Durable Corrosion Resistant Finish) - Chromed Firing Pin - Forward Assist - Dust Cover - 30 Round PMAG - Rifling: 1/9 6 groove