The TacFire BU3008 is an 8-inch upper receiver chambered in .300 AAC Blackout. This upper includes a bolt carrier group (BCG), making it a complete assembly ready for installation on compatible lower receivers.Key FeaturesIncluded BCG: Comes complete with a bolt carrier group for easy installation.Barrel Length: Features an 8-inch barrel suitable for compact setups.Caliber: Chambered in .300 AAC Blackout for versatile shooting options.Rate of Twist: 1:8" twist rate for stability and accuracy with a variety of bullet weights.