The BCM AR-15 Enhanced Fluted Barrel in 300 Blackout offers all the performance and quality that is expected from a BCM product. The Enhanced profile has a continuous taper which lends to a lightweight, balanced, and high performing barrel, and the fluting to the rear of the gas block helps to disperse heat and aid in the keeping the barrel weight down. Caliber: 300 Blackout Length: 9in. Gas System Length: Pistol Twist Rate: 1:7 Gas Block Diameter: .750 Exterior Finish: Manganese Phosphate Bore Chamber Finish: Chrome Lined Muzzle Threads: 5/8x24 BCM has taken great care to ensure the best possible performance and interchangeabili Mfg: Bravo Company