Green Mountain 9mm AR-15 Barrel 10.5" M4 Nitride - GM-M4-9

Upgrade your AR-15 build with the precision-engineered Green Mountain 9mm 10.5″ M4 Nitride barrel. Designed specifically for 9x19mm blowback-operated platforms, this barrel delivers reliable performance and accuracy for tactical, competition, or recreational shooting.

Key Features and Benefits

• Nitride/Melonite Finish: Provides exceptional corrosion resistance and reduced friction for smoother cycling and extended service life in demanding conditions.
• M4 Profile: Balances weight and rigidity for improved handling without sacrificing durability, ideal for compact builds.
• 1:10 Twist Rate: Optimizes stabilization for a wide range of 9mm bullet weights, ensuring consistent accuracy downrange.
• Blowback Gas System: Eliminates the need for a gas block or tube, simplifying assembly and reducing maintenance points.
• 1/2×36 Muzzle Threads: Compatible with popular 9mm muzzle devices and suppressors for enhanced versatility.

Technical Specifications

• Barrel Length: 10.5 inches
• Cartridge Compatibility: 9x19mm / 9mm
• Platform: AR-15
• Finish: Black Nitride
• Steel Type: 41V50
• Weight: 22 ounces

Why Choose This Barrel?

This Green Mountain barrel addresses common pain points in 9mm AR builds, such as excessive fouling, inconsistent accuracy, and complex gas system setups. The nitride treatment resists wear from high-volume firing, while the proven 41V50 steel construction ensures long-term reliability. Whether you’re assembling a compact home-defense pistol or a range-ready SBR, this component provides a solid foundation for dependable function.

Manufactured to exacting standards by a trusted U.S. barrel maker, it integrates seamlessly into standard AR-15 upper receivers for blowback 9mm configurations.

Installation and Compatibility Notes

Requires a compatible 9mm bolt carrier group and magazine well adapter or dedicated lower. Always verify headspace and function with your specific components.