Wilson Combat AR-15 Barrel 6.8 SPC II 11.3 Medium Taper 1:11 Twist Stainless. This AR-15 barrel is machined from 416R Stainless Steel for improved accuracy and longevity. It features a Ranger profile for light weight while maintaining rigidity, a hand-polished bore and feed ramps, a precision muzzle crown, and a chamber and gas port optimized for reliability. 5/8-24 threaded muzzle.