Chambered in 5.56 NATO, the TacFire BU-556-7 Pistol Upper Assembly includes a 7-inch black nitride barrel and a black anodized 7075-T6 aluminum receiver. This complete upper assembly is designed for AR-platform rifles and includes a bolt carrier group, ensuring a straightforward installation on your lower receiver.Key FeaturesIncluded Bolt Carrier Group: Comes with a bolt carrier group for immediate use.Barrel Finish: Features a durable black nitride finish that enhances barrel longevity.Optic Ready: Sights are not included, but the upper is ready for optic installation.