The TacFire Pistol Upper Assembly is a complete, plug-and-play solution chambered in 300 Blackout. It features a 10 4150 Chrome Moly Steel barrel with a black nitride finish and a 1:8 twist rate. Built on a forged 7075-T6 aluminum receiver with a black anodized finish, it includes a 9 M-LOK free-float slim rail and an A2 flash hider. This assembly comes fully built with a standard M16 profile bolt carrier group and a pistol-length gas system, making it ready to be pinned onto a compatible AR-platform lower for reliable cycling of subsonic and supersonic loads. Note: The pistol-length gas system is specifically optimized for the pressure curves of the .300 BLK cartridge to ensure reliable operation across various bullet weights.