Conquer close-quarters with this compact 10.5" .300 Blackout Complete Upper Receiver. Featuring a 10.5" barrel with a 1:7 twist rate this upper ensures optimal stabilization for both subsonic and supersonic rounds making it ideal for tactical hunting or suppressed AR15 pistol builds. The 10" M-Lok handguard provides a lightweight modular platform for mounting accessories while the nitride-finished bolt carrier group delivers smooth cycling enhanced durability and low maintenance. Complete with a charging handle and built to Mil-Spec standards this upper is ready to pair with any AR15 Mil-Spec lower receiver for a seamless high-performance setup. Caliber: .300 BLK Barrel Profile: Medium Muzzle Thread: 5/8X24 Twist Rate: 1/7 Gas System: Pistol Material: 4150 Handguard Length: 10 in. Country of Origin: U.S.A