The Tiger Rock Inc. BR377-N AR-300BLK/300AAC 8.5" Rifle Barrel stands as a pinnacle of precision and performance. Crafted from high-grade 4150 gun-quality heat-treated steel, this barrel is treated with a robust Black Nitride finish, offering superior durability and resistance to corrosion. Engineered for .300 BLK (AAC Blackout), it features an optimal 1:8 twist rate and a .750" gas block diameter, ensuring efficient cycling for enhanced shooting experience. It includes a pistol gas system with a 0.125" gas hole diameter, alongside a 5/8"x24 thread pitch for compatibility with multiple muzzle devices. Proudly made in the USA, this barrel is a perfect fit for any AR-15 platform. Length: 8.5" .300 BLK (AAC Blackout) 1:8 Twist .750" gas block diameter Pistol gas system with a 0.125" gas hole diameter 5/8"x24 Thread Pitch 4150 gun quality heat treated steel Black Nitride finish Made in the U.S.A. Fits: AR-15 Elevate your shooting precision with the Tiger Rock Inc. rifle barrel, showcasing exceptional American craftsmanship.