Ballistic Advantage Performance Series Barrel 5.56x45 11.3 inch Hanson Carbine 1-7 Twist Black. 56 chambered 11.3 inch Performance Series Barrel is machined from 4150 Chrome Moly Vanadium steel with a QPQ Corrosion Resistant Finish. Our performance series barrels feature a Nickel Boron Coated Extended M4 Feed Ramp Extension. Hanson Series Barrels feature our proprietary BA Hanson profile and include a pinned lo-pro gas block. Hanson barrels are not designed to work with aftermarket piston kits. Specifications for Ballistic Advantage Performance Series 5.56x45mm Barrel: Manufacturer: Ballistic Advantage Color: Black Finish: QPQ Corrosion Resistant Fabric/Material: 4150 CMV Caliber: 5.56x45mm NATO Barrel Length: 11.3 in Barrel Profile: Hanson Gas System Length: Carbine Length Gas Block Journal Size-Diameter: .750 in Threads per Inch: 1/2x28 Barrel Twist Rate: 1-7 Gun Model: AR-15 Weight: 21 oz Country of Origin: USA Package Contents: Ballistic Advantage 556032F Performance Series 5.56x45mm Barrel What firearm models does the manufacturer say Ballistic Advantage Performance Series 5.56x45mm Barrel is compatible with? The manufacturer says that Ballistic Advantage Performance Series 5.56x45mm Barrel is compatible with AR-15Ballistic Advantage BABL556032F: Performance Series Barrel 5.56x45 11.3 inch Hanson Carbine 1-7 Twist Black