The CMMG Dissent MK4 is a semi-automatic AR-pistol chambered in .300 AAC Blackout. It has a 6.5-inch barrel, an aluminum frame, and ships in a tungsten cerakote finish. At 4.60 lbs and 14.7 inches overall, it's one of the lighter and more compact options in this caliber. The optic-ready top has no included sights; an ambidextrous safety is standard. 
 

Key Specifications 

• Model: Dissent MK4 
• Caliber: .300 AAC Blackout 
• Action: Semi-Automatic 
• Capacity: 30+1 rounds 
• Barrel Length: 6.5 inches 
• Overall Length: 14.7 inches 
• Weight: 4.60 lbs 
• Frame Material: Aluminum 
• Finish Color: Tungsten 
• Sights: Optic Ready (none included) 
• Safety: Ambidextrous 
   

Features 

The 6.5-inch barrel keeps the pistol short and the tungsten finish is more durable than standard anodizing. .300 BLK runs both supersonic and subsonic loads effectively from a short barrel, making it a practical suppressor host. The ambidextrous safety and optic-ready flat-top give left-handed shooters a full-featured platform and let users mount whatever optic they prefer without adapters. The 30+1 capacity is standard for AR-15-pattern pistols. 
 

Who It's For 

Shooters who want a lightweight, short .300 BLK pistol for suppressed use, range work, or as a compact defensive firearm. The low weight (4.60 lbs) relative to most AR-pistols at this barrel length is a genuine differentiator.

The CMMG Dissent MK4 in .300 Blackout with a tungsten finish gets positive reviews focused on build quality, finish durability, and the compact form factor. The tungsten cerakote is consistently noted as a step above standard anodizing. At 4.60 lbs, it's lighter than most comparable AR-pistols, and owners appreciate the ergonomics and control layout.

The .300 BLK caliber's suppressor compatibility is frequently mentioned as a reason for choosing this model specifically. Range performance is generally reported as accurate and reliable.

The main reservation in buyer discussions is price. The Dissent MK4 sits at the higher end of the AR-pistol market, and some potential buyers compare it unfavorably against less expensive .300 BLK options. Those who own it tend to justify the cost with the fit, finish, and reliability. Weight and balance get occasional mentions, a few users note it handles differently than larger AR-pistols, but this is rarely a complaint, more an adjustment.