Green Mountain 5.56 AR-15 Barrel 10.3" M4 Phosphate - GM-M50

Upgrade your AR-15 build with the Green Mountain 5.56 AR-15 Barrel 10.3″ M4 Phosphate, a compact and durable option engineered for precision and reliability in demanding tactical applications. This barrel combines mil-spec construction with practical features that enhance accuracy, longevity, and ease of maintenance, making it an excellent choice for short-barreled rifles or pistol configurations.

Key Features

• Chrome-lined bore and chamber for superior corrosion resistance and extended service life, even under heavy use or adverse conditions.
• M4 profile barrel optimized for balance between weight and strength, providing a proven contour trusted in military and law enforcement applications.
• 1:7 twist rate stabilizes a wide range of bullet weights, including heavier 62gr and 77gr projectiles for improved accuracy at various ranges.
• Carbine-length gas system ensures reliable cycling with 5.56 NATO ammunition in this compact 10.3″ length.
• Phosphate finish over the exterior delivers a rugged, non-reflective surface that resists wear and blends seamlessly with tactical setups.

Specifications

• Barrel Length: 10.3 inches
• Cartridge Compatibility: 5.56 NATO / .223 Remington
• Twist Rate: 1:7
• Gas System: Carbine
• Gas Block Journal: 0.75 inches
• Muzzle Thread Pattern: 1/2×28
• Finish: Phosphate with chrome-lined bore and chamber
• Platform: AR-15
• Weight: 22 ounces

Why Choose This Product

Short-barreled AR-15 builds often face challenges with reliability and velocity, but this Green Mountain barrel addresses them through its precisely matched carbine gas system and robust construction. The chrome lining reduces fouling and simplifies cleaning, while the 1:7 twist delivers consistent performance across common defensive and training loads. Its compact size improves maneuverability without sacrificing the durability needed for repeated firing sessions.

Whether you’re assembling a home-defense setup, building an SBR, or customizing a competition rifle, this barrel provides a solid foundation that prioritizes function and longevity.

Invest in quality components that enhance your firearm’s performance—select the Green Mountain 5.56 AR-15 10.3″ M4 Phosphate Barrel for your next project.