Green Mountain 5.56 AR-15 Barrel 20" M4 A2 Phosphate - GM-M16
$194.95
Out of stock
Engineered for precision and reliability, the Green Mountain 5.56 AR-15 Barrel 20″ M4 A2 Phosphate delivers the performance serious builders demand in a classic M4-style profile. This button-rifled barrel, constructed from durable 41V50 chrome moly vanadium steel, provides exceptional accuracy and longevity for AR-15 platforms.
Key Features
- Chrome-lined bore and chamber for superior corrosion resistance and extended service life even under heavy use
- M4 A2 government profile balances weight and rigidity while maintaining the authentic look and feel of military-spec barrels
- Rifle-length gas system ensures smooth, reliable cycling with standard 5.56 NATO ammunition
- 1:7 twist rate stabilizes a wide range of bullet weights, from 55gr to 77gr projectiles
- Phosphate finish offers a tough, non-reflective exterior that resists wear and environmental exposure
Technical Specifications
- Caliber: 5.56 NATO
- Length: 20 inches
- Twist Rate: 1:7
- Gas System: Rifle length
- Gas Block Journal: 0.75 inches
- Muzzle Threading: 1/2×28
- Profile: Government / M4 A2
- Finish: Phosphate with chrome-lined bore and chamber
- Weight: 37.6 oz
- Material: 41V50 mil-spec chrome moly vanadium steel
Why Choose This Barrel
Whether restoring a classic M4 clone or building a reliable duty or range rifle, this barrel addresses common pain points like inconsistent accuracy, premature wear, and difficult maintenance. The chrome lining protects against the corrosive effects of modern ammunition while the 1:7 twist delivers tight groups across common loads. Its rifle gas system promotes consistent operation without the over-gassing issues sometimes seen in shorter systems.
Built to mil-spec standards, it integrates seamlessly with standard AR-15 upper receivers featuring M4 feed ramps for reliable feeding.
Benefits for the Shooter
- Enhanced durability reduces the need for frequent barrel replacements
- Versatile twist rate supports both plinking and precision shooting
- Authentic profile maintains balance and handling characteristics familiar to military and law enforcement users
Invest in a barrel trusted by competitive shooters and builders for its consistent quality and performance. Upgrade your AR-15 with this precision component today and experience the difference a quality barrel makes.
| Weight | 37.6 oz |
|---|---|
| Dimensions | 20 in |
| Finish | Phosphate + Chrome Lined |
| Barrel Profile | Government / SOCOM |
| Cartridge Compatibility | 5.56 NATO |
| Gas Block Journal | 0.75 |
| Barrel Length | 20 |
| Gas System Length | Rifle |
| Platform | AR-15 |
| Twist Rate | 1:7 |
| Muzzle Thread Pattern | 1/2×28 |
| MPN | GM-M16 |
Compliance
NFA (National Firearms Act) compliance is crucial for legal ownership and transfer of regulated firearms and accessories like short-barreled rifles, suppressors, and certain types of ammunition, ensuring adherence to federal regulations to avoid legal penalties and ensure responsible firearm ownership.
