Faxon Firearms .300 Blackout 7.5" Gunner Profile AR-15 Barrel. Machined from 4150 Mil-Spec steel and finished with a black nitride finish, this 7.5" Gunner-profile barrel is designed for AR-15 platform pistols and rifles. Chambered in .300 Blackout and button-rifled, it features a pistol-length gas system, 1:8 twist rate, 5/8" 24 muzzle threads, M4 barrel extension, and an 11 target crown. The Gunner profile blends Government and Pencil characteristics to move balance rearward for reduced fatigue and improved handling during long shooting sessions. Features Barrel Material: 4150 CMV Barrel Type: Button Rifled Caliber: .300 Blackout Twist Rate: 1:8 Length: 7.5" Profile: Gunner (rearward balance for reduced fatigue) Gas System: Pistol-length Inside Finish: Nitride Outside Finish: Nitride Muzzle Thread: 5/8" 24 TPI Gas Block Diameter (journal): .750" Gas Block Journal Length: 1.9" Barrel Extension: M4 Weight: 87 lbs Inspection: Magnetic Particle Inspected Muzzle: 11 target crown Manufacturer: Faxon Firearms Product Specifications Barrel Length: 7-1/2" (7.5") Barrel Thread Pitch: 5/8" 24 TPI Brand: Faxon Firearms Caliber: .300 Blackout Finish / Color: Black (Nitride) Firearm Type: Pistol, Rifle (AR-15) Material: 4150 Steel Models Fit: AR-15