The CMMG DISSENT Mk4 is a semi-automatic AR-pattern pistol chambered in .300 Blackout with a 6.5-inch barrel and a pistol brace. It is a short-barreled configuration; transfer requires additional federal paperwork. The magazine capacity is 33 rounds. 
 

Key Specifications 

• Brand: CMMG 
• Model: DISSENT Mk4 
• Caliber: .300 AAC Blackout 
• Action: Semi Auto 
• Barrel Length: 6.5 inches 
• Capacity: 33 rounds 
• Color: Black (Armor Black) 
   

Detailed Features 

• 6.5-inch barrel 
• Pistol brace included 
• 33-round capacity 
• Armor Black finish 
• AR-pattern Mk4 lower platform

Owners of the CMMG DISSENT Mk4 in .300 Blackout frequently highlight the combination of the short barrel and the brace as making it a highly compact package. The 6.5-inch barrel in .300 Blackout is a common choice for suppressor use, and many buyers pick this configuration specifically with a can in mind, noting the cartridge was designed for short barrels.

The CMMG Mk4 platform generally draws positive marks for build quality. The DISSENT in particular gets attention for the radial delayed blowback system, which owners say runs reliably with both supersonic and subsonic loads without adjustments. A recurring criticism is that the brace, while functional, feels like a compromise compared to a traditional stock.

Value opinion is divided. Those who want a purpose-built short suppressor host in .300 Blackout tend to view the price as fair for the platform. Buyers shopping casually sometimes feel the premium over competing AR pistols is hard to justify on paper until they handle one in person.