Optimize your AR-15 build with the precision-engineered Green Mountain 5.56 AR-15 Barrel 10.5″ M4 Phosphate. Designed for tactical enthusiasts and competitive shooters seeking reliable performance in a compact package, this barrel delivers exceptional accuracy and durability for close-quarters applications and versatile rifle configurations.
Key Features
- Chrome-lined bore and chamber for superior corrosion resistance, easier cleaning, and extended service life under high-volume use.
- Phosphate finish provides a durable, non-reflective coating that enhances protection against wear and environmental factors.
- M4 profile balances strength and reduced weight for improved handling without sacrificing rigidity.
- 1:7 twist rate stabilizes a wide range of bullet weights, including heavier projectiles for optimal ballistic performance.
- Carbine-length gas system ensures reliable cycling with standard AR-15 components.
Technical Specifications
- Barrel Length: 10.5 inches
- Chamber: 5.56 NATO
- Twist Rate: 1:7
- Gas System: Carbine
- Gas Block Journal: 0.75 inches
- Muzzle Thread: 1/2×28
- Material: 4150 Chrome Moly Vanadium steel
- Finish: Phosphate exterior with chrome-lined interior
- Weight: 23.2 ounces
Why Choose This Barrel
This compact 10.5-inch barrel excels in scenarios requiring enhanced maneuverability, such as home defense or tactical training, while maintaining the accuracy and reliability expected from Green Mountain Rifle Barrels. The combination of a chrome-lined bore and phosphate coating addresses common pain points like fouling buildup and rust, allowing for consistent performance across thousands of rounds. Its M4 contour and carbine gas system integrate seamlessly with standard AR-15 uppers, minimizing the need for custom modifications.
Whether upgrading an existing platform or starting a new build, this barrel provides the foundation for a dependable, high-performing firearm.


