The AR-STONER 6mm ARC Barrel is excellent for this potent and accurate cartridge. Manufactured from 416R Stainless Steel, this 1 in 8" Twist, M4 contour barrel gives you high quality at a great value. Additional features include feed ramps and a 5/8"-24 threaded muzzle. The barrel extension and locator pin are both included and installed at the factory. For an accurate barrel at an affordable price, look no further than the AR-Stoner Barrel. Features1 in 8" TwistM4 ContourManufactured from 416R Stainless Steel