Finish: Black Anodized Hardcoat – Caliber: 300 Blackout – Barrel: Diamondback Barrels 16 4150 Heavy Chrome-Moly Free Float Black Nitride No Thread – Barrel Twist Rate: 1:8 RH – Gas System: Pistol Length Gas System – Bolt Carrier: 5.56 Sporter Model Shot-Peened Magnetic Particle Inspected Mil Spec 8620 carrier – Lower Receiver: Forged 7075 T-6 Aluminum – Upper Receiver: A3 Flattop Forged 7075 T6 Aluminum – Handguard: Aluminum 12 M-LOK Rail – Stock: Thordsen Featureless Gen II FRS-15 – Magazine: 10 Round MagPul PMAG