CMMG 33A380C-AB Dissent MK3 .300 Blackout 12.5" 20-Round Rifle

The CMMG 33A380C-AB Dissent MK3 .300 Blackout 12.5" rifle is purpose-built for close-quarters operations, home defense, and specialized tactical applications where hearing safety and target precision matter equally. Chambered in .300 Blackout—a cartridge engineered for subsonic performance—this platform delivers consistent, controllable ballistics in tight environments without the need for hearing protection. The 12.5-inch barrel balances velocity retention with maneuverability, making it ideal for operators working in confined spaces, vehicles, or structures where a full-length rifle becomes a liability.

The Dissent MK3 platform features a flat-top receiver configuration compatible with standard Picatinny rails for optic and accessory mounting, allowing you to customize the rifle for your specific mission profile. At 11.8 pounds with a compact 39.6-inch overall length, this rifle maintains the ergonomic controls and reliability of the direct-impingement system while staying light enough for extended carry and CQB work. The 20-round magazine capacity provides adequate ammunition on-target without requiring frequent reloads, critical in time-sensitive scenarios where magazine changes create tactical delays.

Law enforcement tactical teams, military designated marksmen, and experienced civilians prioritizing low-noise, high-reliability platforms will find the CMMG 33A380C-AB Dissent MK3 .300 Blackout rifle fully compatible with standard AR-platform accessories, ammunition, and maintenance protocols. Its proven pedigree in professional service roles—combined with the inherent accuracy advantages of the .300 Blackout cartridge—makes it a trusted choice for operators who refuse to compromise on performance. Proper eye and hearing protection remain essential regardless of subsonic ammunition selection, and operators should verify all local, state, and federal firearm regulations before purchase and deployment.