Green Mountain 9mm AR-15 Barrel 10.5" M4 Finned Nitride - GM-M59

Build a high-performance 9mm AR-15 pistol or short-barreled rifle with the Green Mountain 10.5″ M4 Finned Nitride barrel. Engineered for reliable function in blowback-operated platforms, this barrel delivers consistent accuracy and enhanced control in a compact package.

Key Features

• Integral Cutts-style compensator machined directly into the barrel reduces muzzle rise and felt recoil for faster follow-up shots.
• Finned M4 profile increases surface area for improved heat dissipation during sustained fire while adding distinctive tactical aesthetics.
• Nitride finish provides exceptional corrosion resistance, wear protection, and a sleek black appearance with minimal maintenance required.
• 1:10 twist rate stabilizes a wide range of 9mm projectiles for optimal accuracy across common defensive and training loads.

Specifications

• Barrel Length: 10.5 inches
• Caliber: 9x19mm / 9mm Luger
• Platform: AR-15
• Gas System: Blowback (no gas block required)
• Twist Rate: 1:10
• Muzzle Threading: 1/2×36
• Profile: Finned M4
• Finish: Nitride / Melonite
• Material: 4140 Chrome Moly steel
• Weight: 22 oz

Why Choose This Barrel

Designed specifically for compact 9mm AR builds, this Green Mountain barrel solves common pain points like excessive recoil and heat buildup in short configurations. The integrated compensator enhances shootability without adding extra length or weight, while the durable nitride treatment ensures long-term reliability in demanding tactical or range environments. Compatible with standard AR-15 uppers and blowback 9mm BCGs, it offers a straightforward upgrade path for builders seeking precision and performance.

Benefits for Your Build

• Enables legal AR pistol or ATF-compliant SBR configurations (verify all local and federal regulations).
• Promotes reliable cycling with a variety of 9mm ammunition types.
• Reduces overall system weight for improved maneuverability.
• Delivers consistent grouping potential thanks to quality rifling and chambering.

Upgrade your next 9mm AR project with this precision-engineered barrel from a trusted American manufacturer.