Green Mountain 5.56 AR-15 Barrel 16" M4 Phosphate - GM-M4

Upgrade your AR-15 build with the reliable Green Mountain 5.56 AR-15 Barrel 16″ M4 Phosphate. Designed for precision and durability, this carbine-length barrel delivers consistent performance in demanding tactical and recreational shooting scenarios.

Key Features

• Chrome-lined bore and chamber with phosphate exterior finish for superior corrosion resistance and extended barrel life
• M4 profile provides a balance of lightweight handling and structural strength for versatile rifle configurations
• 1:9 twist rate stabilizes a wide range of 5.56 NATO and .223 Remington ammunition for improved accuracy
• Carbine-length gas system ensures reliable cycling and smooth operation in semi-automatic platforms
• 0.75″ gas block journal and 1/2×28 muzzle thread pattern allow easy installation of standard gas blocks and muzzle devices

Specifications

• Platform: AR-15
• Barrel Length: 16 inches
• Cartridge Compatibility: 5.56 NATO
• Twist Rate: 1:9
• Finish: Phosphate + Chrome Lined
• Barrel Profile: M4
• Gas System Length: Carbine
• Gas Block Journal: 0.75 inches
• Muzzle Thread Pattern: 1/2×28
• Weight: 31.2 oz

Why Choose This Product

This barrel addresses common shooter concerns like barrel wear from high-volume firing and environmental exposure. The chrome lining protects the bore during rapid fire, while the phosphate coating resists rust and oxidation. Its M4 contour offers excellent heat dissipation without excessive weight, making it ideal for both home defense setups and range sessions. The 1:9 twist provides reliable stabilization for popular bullet weights, enhancing shot-to-shot consistency.

Built to milspec standards by Green Mountain, this barrel integrates seamlessly into standard AR-15 upper receivers for a dependable, accurate firearm.

FAQs

• What ammunition works best with the 1:9 twist?The 1:9 twist rate effectively stabilizes 5.56 NATO loads from 55gr to 62gr, offering versatility for both target shooting and defensive applications.
• Is this barrel compatible with standard AR-15 components?Yes, the 16″ carbine gas system, 0.75″ journal, and 1/2×28 threading are designed for direct compatibility with most AR-15 gas blocks, handguards, and muzzle devices.
• How does the chrome lining benefit performance?Chrome lining reduces friction and fouling in the bore and chamber, promoting easier cleaning, longer service life, and consistent accuracy even after thousands of rounds.