The AR-STONER 6.5 Grendel Barrel is chambered in 6.5 Grendel and manufactured from 4150 Chrome Moly Vanadium steel. This heavy contour barrel features a 1 in 8 twist, 10.5 inch length, M4 feed ramps, and a 5/8-24 threaded muzzle. The barrel extension and locator pin are included and installed at the factory.