Threaded pistol barrels chambered in 9mm and 45 Auto. Precision CNC machined from 416R stainless steel with a black Isonite QPQ finish, all AAC silencer ready barrels feature cut broach rifling for compatibility with jacketed and lead ammunition. AAC silencer ready barrels are designed to drop in and function with no fitting required, and feature chamber dimensions that will accept all commercial, SAAMI specification ammunition. Available with unified threads (1/2×28 for 9mm & .578×28 for 45 Auto) and left hand metric muzzle thread profiles (M13.5x1LH for 9mm & M16x1LH for 45 Auto) where applicable. Each threaded barrel comes with a knurled thread protector cap. Mfg: Advanced Armament SPECS: Material – 416R stainless steel. Rifling – cut broach. Finish – Black Isonite. Threads – 9mm barrels available in 1/2×28 and Metric 13.5x1LH threads.45ACP barrels available in .578×28 threads (Glock 21 also available in M16x1LH).