Availability: In Stock
The CMMG 16" AR-15 300 AAC Blackout barrel transforms your standard rifle into a potent mid-range platform without the complexity of a full build. Built on the modern 300 BLK cartridge, this barrel gives you substantial power — comparable to 7.62x39 — while keeping your existing bolt, carrier, and magazines in play. That's the appeal of 300 Blackout: serious capability, minimal downtime, and complete compatibility with your current AR infrastructure.
Engineered for real-world use, this 16-inch barrel rides a multi-role contour and features a 1:7 twist rate that stabilizes everything from light 110-grain varmint rounds to heavy 220-grain subsonic loads. The carbine-length gas port sits in the standard position, so it cycles reliably with common M4 gas tubes and all supersonic ammunition. You get a 5/8"-24 muzzle thread, opening the door to mainstream flash hiders and brakes. Chrome moly steel treated with CMMG's Wasp nitriding process handles both suppressed fire and high-volume shooting without premature wear or corrosion — a practical choice if you're running serious round counts or pushing your rifle in harsh conditions.
Swap this barrel onto your existing receiver, dial in your load or ammo, and you've got a versatile 300 BLK platform ready for hunting, suppressed precision work, or tactical training. No special magazines, no exotic parts, no gunsmith headaches.
| Caliber | 300 AAC Blackout (300 BLK) |
| Barrel Length | 16 inches |
| Twist Rate | 1:7 |
| Gas System | Carbine-length |
| Material | Chrome Moly Steel |
| Finish | Matte (Wasp nitrided) |
| Muzzle Thread | 5/8"-24 |
| Contour | Multi-Role |
| Bolt/Carrier Compatibility | Standard AR-15 (.223/5.56 bolt and carrier) |
| Magazine Compatibility | Standard AR-15 magazines at full capacity |
Yes. The 300 BLK cartridge uses the same bolt face and carrier as .223/5.56 AR-15s, so no modifications to your lower receiver or magazine supply are needed. This is a drop-in barrel swap.
The 1:7 twist is rated to stabilize bullets from 110 grains on the light end through 220 grains on the heavy end, covering both supersonic and subsonic loads across the 300 BLK spectrum.
This 16-inch barrel has the gas port in the standard carbine position and is optimized for all supersonic ammunition and standard M4 gas systems. While 300 BLK is famous for subsonic performance with suppressors, you'll want to verify your complete setup — gas tube length, buffer weight, and ammunition — to ensure reliable cycling if you plan to run subsonic rounds.
The barrel features 5/8"-24 muzzle threads, which is the standard for .308-pattern accessories. You can use most AR-10 style flash suppressors, brakes, and suppressors that share this thread pitch.
SKU: 115649248 • Width: 1.6in • Height: 1.5in • Depth: 18.2in • Weight: 2.25oz
Availability: In Stock
The CMMG 16" AR-15 300 AAC Blackout barrel transforms your standard rifle into a potent mid-range platform without the complexity of a full build. Built on the modern 300 BLK cartridge, this barrel gives you substantial power — comparable to 7.62x39 — while keeping your existing bolt, carrier, and magazines in play. That's the appeal of 300 Blackout: serious capability, minimal downtime, and complete compatibility with your current AR infrastructure.
Engineered for real-world use, this 16-inch barrel rides a multi-role contour and features a 1:7 twist rate that stabilizes everything from light 110-grain varmint rounds to heavy 220-grain subsonic loads. The carbine-length gas port sits in the standard position, so it cycles reliably with common M4 gas tubes and all supersonic ammunition. You get a 5/8"-24 muzzle thread, opening the door to mainstream flash hiders and brakes. Chrome moly steel treated with CMMG's Wasp nitriding process handles both suppressed fire and high-volume shooting without premature wear or corrosion — a practical choice if you're running serious round counts or pushing your rifle in harsh conditions.
Swap this barrel onto your existing receiver, dial in your load or ammo, and you've got a versatile 300 BLK platform ready for hunting, suppressed precision work, or tactical training. No special magazines, no exotic parts, no gunsmith headaches.
| Caliber | 300 AAC Blackout (300 BLK) |
| Barrel Length | 16 inches |
| Twist Rate | 1:7 |
| Gas System | Carbine-length |
| Material | Chrome Moly Steel |
| Finish | Matte (Wasp nitrided) |
| Muzzle Thread | 5/8"-24 |
| Contour | Multi-Role |
| Bolt/Carrier Compatibility | Standard AR-15 (.223/5.56 bolt and carrier) |
| Magazine Compatibility | Standard AR-15 magazines at full capacity |
Yes. The 300 BLK cartridge uses the same bolt face and carrier as .223/5.56 AR-15s, so no modifications to your lower receiver or magazine supply are needed. This is a drop-in barrel swap.
The 1:7 twist is rated to stabilize bullets from 110 grains on the light end through 220 grains on the heavy end, covering both supersonic and subsonic loads across the 300 BLK spectrum.
This 16-inch barrel has the gas port in the standard carbine position and is optimized for all supersonic ammunition and standard M4 gas systems. While 300 BLK is famous for subsonic performance with suppressors, you'll want to verify your complete setup — gas tube length, buffer weight, and ammunition — to ensure reliable cycling if you plan to run subsonic rounds.
The barrel features 5/8"-24 muzzle threads, which is the standard for .308-pattern accessories. You can use most AR-10 style flash suppressors, brakes, and suppressors that share this thread pitch.
SKU: 115649248 • Width: 1.6in • Height: 1.5in • Depth: 18.2in • Weight: 2.25oz