The AR-9 BCG is a bolt carrier group built for 9mm AR-style pistol-caliber carbines. It includes the carrier, bolt, firing pin, and extractor. This BCG works with AR-15 upper receivers and 9mm barrels. It pairs with 9mm magazines and blowback lower receivers. Builders use it for home defense, competition, and recreational shooting. The AR-9 BCG delivers smooth cycling and reliable extraction. It fits most standard AR-9 builds.