Caliber: .300 Blackout - Finish: Black Anodized Hardcoat - Barrel: Diamondback Barrels 16 4140 Chrome-Moly Free Float Black Nitride - Barrel Twist Rate: 1:8 RH - Gas System: ?Carbine Length Gas System - Bolt Carrier: Azimuth 5.56 Sporter Model Shot-Peened Magnetic Particle Inspected Mil Spec 8620 carrier - Lower Receiver: Forged 7075 T6 Aluminium - Upper Receiver: A3 Flattop Forged 7075 T6 Aluminum - Handguard: Aluminum 12 M-LOK Rail - Pistol Grip: A2 Style Standard Grip - Stock: Roger's Super-Stoc - Mag: 30 Round Metal Mag - Weight: 6.65 lbs. - Overall Length (Stock Collapsed): 32 - Overal Length (Stock Expanded): 36 - Flash Hider: A2 Flash Hider