Engineered for precision and reliability in 9mm AR-15 pistol caliber carbine builds, the Green Mountain 16" M4 Finned Nitride barrel delivers consistent performance for tactical and recreational shooters. This blowback-operated barrel combines a durable nitride finish with an M4 contour and integrated fins to optimize heat management and handling during extended sessions. Key Features Nitride / Melonite finish provides exceptional corrosion resistance and a smooth, low-maintenance surface that withstands harsh conditions while simplifying cleaning. M4 finned profile enhances heat dissipation and reduces weight compared to heavier contours, improving balance and control in dynamic shooting scenarios. 1:10 twist rate stabilizes a wide range of 9mm projectiles for improved accuracy and versatility across different ammunition types. 16-inch barrel length offers an optimal balance of velocity, maneuverability, and compliance for many AR-15 platforms. 1/2x36 muzzle threads allow easy attachment of compatible 9mm muzzle devices for recoil management and customization. Technical Specifications Finish: Nitride / Melonite Barrel Profile: M4 Finned Cartridge Compatibility: 9x19mm / 9mm Gas System: Blowback (no gas block required) Platform: AR-15 Twist Rate: 1:10 Muzzle Thread Pattern: 1/2x36 Weight: 28 oz Length: 16 in Why Choose This Green Mountain Barrel Designed specifically for 9mm AR-15 builds, this barrel addresses common pain points like excessive heat buildup and maintenance demands. The finned M4 profile promotes rapid cooling for sustained fire, while the nitride treatment resists wear and fouling. Whether you're assembling a home-defense PCC or a range-ready carbine, the 1:10 twist ensures reliable feeding and accuracy without compromising on durability. Green Mountain's reputation for quality manufacturing means you get a barrel that integrates seamlessly into standard AR-15 uppers for blowback 9mm configurations. Upgrade your AR-15 project with this precision-crafted 9mm barrel to achieve superior handling, longevity, and performance in your next build.