CMMG145479043
Cmmg Dissent 55A520B-Ab Br4 556 16.1 *Ca Armbk$1,833.02
Availability: In Stock
The CMMG Dissent BR4 300 Blackout carbine is a modern, do-it-all platform built around one of the most versatile cartridges in use today. Whether you're running subsonic rounds through a suppressor for stealth, pushing supersonic loads for hunting, or putting rounds downrange at the range, this 16.1-inch rifle is engineered to adapt to your mission. The Dissent line is CMMG's answer to shooters who want a purpose-built 300 BLK platform that doesn't sacrifice ergonomics, modularity, or shootability.
Built on CMMG's proprietary BR4 billet receiver set machined from 7075 T6 aluminum, the Dissent combines a direct impingement operating system with a carbine-length gas system tuned for reliable function across the subsonic-to-supersonic spectrum. The 16.1-inch barrel features a 1:7 twist rate optimized for the full range of 300 BLK projectiles, and it's crowned with a CMMG ZEROED muzzle brake (5/8-24 threads) that helps manage recoil and improves handling. A full-length Picatinny rail on top gives you mounting flexibility for any optic or sighting system, while the 15-inch M-LOK handguard provides ample real estate for accessories and a modern ergonomic grip.
The Dissent side-charging handle keeps the receiver profile clean and offers left and right operation, and the reversible safety selector accommodates both right and left-handed shooters. Trigger duty falls to a CMMG ZEROED drop-in single-stage unit—crisp and predictable out of the box. Two 10-round Magpul PMags, an adjustable gas block for tuning, and a Magpul SGA stock complete the package. Finished in Cerakote and tipping the scales at 7.8 pounds, this is a rifle that feels as good as it shoots.
| Caliber | .300 Blackout |
| Platform | CMMG BR4 |
| Operating System | Direct Impingement (Compact Action) |
| Barrel Length | 16.1 inches |
| Barrel Twist | 1:7 |
| Barrel Material | 4140CM, carbine contour |
| Muzzle Device | CMMG ZEROED muzzle brake |
| Muzzle Thread | 5/8-24 |
| Gas System | Carbine length, adjustable gas block (0.750) |
| Upper Receiver | DISSENT 7075 T6 aluminum |
| Lower Receiver | BR4 billet 7075 T6 aluminum |
| Handguard | CMMG 15-inch proprietary, M-LOK compatible |
| Rail System | Full-length Picatinny on top |
| Charging Handle | DISSENT side charger, reversible |
| Trigger | CMMG ZEROED drop-in single-stage |
| Trigger Guard | Integrated |
| Safety | Reversible cross-bolt selector |
| Stock | Magpul SGA (Remington 870-pattern) |
| Magazines Included | Two Magpul 10-round PMags |
| Finish | Cerakote |
| Weight | 7.8 lbs |
| Length | 38.1 inches |
This rifle is chambered in .300 Blackout and designed to run both subsonic (typically 220 grains and slower) and supersonic (125–150 grain) loads reliably. The 1:7 barrel twist and adjustable gas block allow you to tune performance across the cartridge's range—critical when you're mixing ammunition types.
Yes. The CMMG Dissent features a 5/8-24 threaded muzzle and a carbine-length gas system, both of which support suppressor use. The adjustable gas block lets you dial in performance with a suppressor installed, especially with subsonic ammunition. A muzzle brake is installed; you can replace it with a suppressor adapter if needed.
The Dissent comes with two Magpul 10-round PMags, a Magpul SGA stock, and is ready to mount an optic on the full-length Picatinny rail. The CMMG ZEROED trigger and muzzle brake are installed.
The side-charging handle and reversible safety selector both accommodate left and right-handed shooters, making the Dissent suitable for either hand.
SKU: 145480056 • Width: 10.15in • Height: 3.1in • Depth: 40.95in • Weight: 7.87oz
Availability: In Stock
The CMMG Dissent BR4 300 Blackout carbine is a modern, do-it-all platform built around one of the most versatile cartridges in use today. Whether you're running subsonic rounds through a suppressor for stealth, pushing supersonic loads for hunting, or putting rounds downrange at the range, this 16.1-inch rifle is engineered to adapt to your mission. The Dissent line is CMMG's answer to shooters who want a purpose-built 300 BLK platform that doesn't sacrifice ergonomics, modularity, or shootability.
Built on CMMG's proprietary BR4 billet receiver set machined from 7075 T6 aluminum, the Dissent combines a direct impingement operating system with a carbine-length gas system tuned for reliable function across the subsonic-to-supersonic spectrum. The 16.1-inch barrel features a 1:7 twist rate optimized for the full range of 300 BLK projectiles, and it's crowned with a CMMG ZEROED muzzle brake (5/8-24 threads) that helps manage recoil and improves handling. A full-length Picatinny rail on top gives you mounting flexibility for any optic or sighting system, while the 15-inch M-LOK handguard provides ample real estate for accessories and a modern ergonomic grip.
The Dissent side-charging handle keeps the receiver profile clean and offers left and right operation, and the reversible safety selector accommodates both right and left-handed shooters. Trigger duty falls to a CMMG ZEROED drop-in single-stage unit—crisp and predictable out of the box. Two 10-round Magpul PMags, an adjustable gas block for tuning, and a Magpul SGA stock complete the package. Finished in Cerakote and tipping the scales at 7.8 pounds, this is a rifle that feels as good as it shoots.
| Caliber | .300 Blackout |
| Platform | CMMG BR4 |
| Operating System | Direct Impingement (Compact Action) |
| Barrel Length | 16.1 inches |
| Barrel Twist | 1:7 |
| Barrel Material | 4140CM, carbine contour |
| Muzzle Device | CMMG ZEROED muzzle brake |
| Muzzle Thread | 5/8-24 |
| Gas System | Carbine length, adjustable gas block (0.750) |
| Upper Receiver | DISSENT 7075 T6 aluminum |
| Lower Receiver | BR4 billet 7075 T6 aluminum |
| Handguard | CMMG 15-inch proprietary, M-LOK compatible |
| Rail System | Full-length Picatinny on top |
| Charging Handle | DISSENT side charger, reversible |
| Trigger | CMMG ZEROED drop-in single-stage |
| Trigger Guard | Integrated |
| Safety | Reversible cross-bolt selector |
| Stock | Magpul SGA (Remington 870-pattern) |
| Magazines Included | Two Magpul 10-round PMags |
| Finish | Cerakote |
| Weight | 7.8 lbs |
| Length | 38.1 inches |
This rifle is chambered in .300 Blackout and designed to run both subsonic (typically 220 grains and slower) and supersonic (125–150 grain) loads reliably. The 1:7 barrel twist and adjustable gas block allow you to tune performance across the cartridge's range—critical when you're mixing ammunition types.
Yes. The CMMG Dissent features a 5/8-24 threaded muzzle and a carbine-length gas system, both of which support suppressor use. The adjustable gas block lets you dial in performance with a suppressor installed, especially with subsonic ammunition. A muzzle brake is installed; you can replace it with a suppressor adapter if needed.
The Dissent comes with two Magpul 10-round PMags, a Magpul SGA stock, and is ready to mount an optic on the full-length Picatinny rail. The CMMG ZEROED trigger and muzzle brake are installed.
The side-charging handle and reversible safety selector both accommodate left and right-handed shooters, making the Dissent suitable for either hand.
SKU: 145480056 • Width: 10.15in • Height: 3.1in • Depth: 40.95in • Weight: 7.87oz