Geissele CHF 5.56mm Barrel 13.9 in Chrome Lined 1/2x28 1-7 Twist Mid Length Tapered. Our barrels are High Pressure Tested (HPT) and Magnetic Particle Inspected (MPI). The accuracy and reliability of Geissele CHF barrels makes them an ideal choice for a hard use duty weapon precision tuned competition gun and everything in between. Specifications for Geissele CHF AR-15 5.56mm Threaded Barrel: Manufacturer: Geissele Color: Chrome Fabric/Material: Chromolly Steel Caliber: 5.56mm Barrel Profile: Tapered Gas Block Journal Size-Diameter: .750 in Threads per Inch: 1/2x28 Barrel Twist Rate: 1-7 Barrel Material: Chrome Moly Vanadium Gun Make: AR Platform Gun Model: AR-15 Package Contents: Geissele CHF AR-15 5.56mm Threaded Barrel What firearm models does the manufacturer say Geissele CHF AR-15 5.56mm Threaded Barrel is compatible with? The manufacturer suggests that Geissele CHF AR-15 5.56mm Threaded Barrel is compatible with AR-15Geissele 05-2989: CHF 5.56mm Barrel 13.9 in Chrome Lined