Green Mountain 5.56 AR-15 Barrel 14.5" M4 Phosphate - GM-M29

Upgrade your AR-15 build with the reliable Green Mountain 5.56 AR-15 Barrel 14.5″ M4 Phosphate. Engineered for precision and durability, this carbine-length barrel delivers consistent performance in demanding tactical and recreational applications.

Key Features and Benefits

• Chrome-lined bore and chamber with phosphate exterior finish for superior corrosion resistance and extended service life, reducing maintenance needs during heavy use.
• M4 profile design balances weight and strength, providing a classic contour that enhances handling without sacrificing rigidity for improved accuracy at range.
• 1:8 twist rate stabilizes a wide variety of 5.56 NATO and .223 Remington ammunition, optimizing bullet flight for better grouping and terminal performance.
• Carbine-length gas system ensures reliable cycling across various loads, minimizing recoil and supporting rapid follow-up shots.

Technical Specifications

• Barrel Length: 14.5 inches
• Platform: AR-15
• Cartridge Compatibility: 5.56 NATO
• Barrel Profile: M4
• Gas System: Carbine
• Gas Block Journal: 0.75 inches
• Twist Rate: 1:8
• Muzzle Thread Pattern: 1/2×28
• Finish: Phosphate with chrome-lined bore and chamber
• Weight: 29 ounces

Why Choose This Barrel

This barrel addresses common pain points for AR-15 builders by offering a proven M4 contour in a compact 14.5-inch length ideal for maneuverability in confined spaces or CQB scenarios. The combination of chrome lining and phosphate coating protects against wear and environmental factors, ensuring dependable function whether you’re at the range, in training, or maintaining home defense readiness. Its standard threading supports a variety of muzzle devices for customization.

Ideal Applications

Perfect for custom AR-15 assemblies where a carbine gas system and M4 profile are preferred. Compatible with standard AR-15 upper receivers and handguards designed for carbine-length barrels.