Green Mountain 300 BLK AR-15 Barrel 12.5" M4 Phosphate - GM-M41
$173.95
Out of stock
Engineered for precision and reliability in compact AR-15 builds, the Green Mountain 12.5″ M4 Profile 300 BLK Barrel delivers exceptional performance for tactical applications, suppressed shooting, and versatile ammunition use. This barrel combines proven manufacturing quality with features that enhance accuracy, durability, and compatibility in pistol-length gas systems.
Key Features and Benefits
- M4 Profile Construction: The classic M4 contour provides an optimal balance of strength and reduced weight, making it ideal for maneuverable short-barreled configurations without sacrificing structural integrity under sustained fire.
- Phosphate Finish: Mag phosphate coating offers superior corrosion resistance and a non-reflective surface, ensuring long-term durability in demanding environments while maintaining a professional tactical appearance.
- 1:7 Twist Rate: Optimized to stabilize a wide range of 300 BLK bullet weights, including heavy subsonic loads for suppressed use, delivering consistent accuracy across supersonic and subsonic ammunition.
- Pistol-Length Gas System: Designed specifically for reliable cycling in shorter barrels, promoting smooth operation and reduced recoil for faster follow-up shots.
- 5/8×24 Muzzle Threading: Standard threading allows seamless attachment of muzzle devices, brakes, or suppressors for enhanced versatility and sound suppression.
Technical Specifications
- Barrel Length: 12.5 inches
- Gas System: Pistol length
- Gas Block Journal: 0.750 inches
- Twist Rate: 1:7
- Platform: AR-15 / M4 compatible
- Finish: Mag Phosphate
- Muzzle Thread Pattern: 5/8×24
- Cartridge: 300 AAC Blackout
- Approximate Weight: 28 oz
Why Choose the Green Mountain 300 BLK Barrel
Green Mountain Rifle Barrels are trusted by builders and manufacturers for their consistent quality and performance. This 12.5″ model addresses common challenges in short-barrel 300 BLK builds by providing reliable gas operation, excellent bullet stabilization, and a rugged finish that withstands harsh conditions. Whether you’re assembling a compact home defense rifle or a suppressed tactical platform, this barrel ensures dependable function and precision.
Upgrade your AR-15 with a barrel built for real-world reliability and performance. Explore compatible uppers and components to complete your custom build today.
| Weight | 28 oz |
|---|---|
| Dimensions | 12.5 in |
| Finish | Mag Phosphate |
| Barrel Profile | M4 |
| Cartridge Compatibility | 300 BLK |
| Gas Block Journal | 0.75 |
| Barrel Length | 12.5 |
| Gas System Length | Pistol |
| Platform | AR-15 |
| Twist Rate | 1:7 |
| Muzzle Thread Pattern | 5/8×24 |
| MPN | GM-M41 |
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.
