SilencerCo AC863: The Glock 21 threaded barrel from Silencer Co is a 4.6 inch replacement barrel made from 416rd stainless steel. This barrel features a black finish along with a .578" x 28 RH thread pattern.
DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.