The CMMG Dissent MK4 is a semi-automatic pistol chambered in .300 AAC Blackout with a 10.5-inch barrel and a tungsten finish. At 18.7 inches overall, it's a compact AR-style pistol that handles both supersonic and subsonic .300 Blackout loads well, which makes it useful whether you're running it suppressed or not. 
 

Key Specifications 

• Model: Dissent MK4 
• Caliber: .300 AAC Blackout 
• Action: Semi-Auto 
• Barrel Length: 10.5 inches 
• Overall Length: 18.7 inches 
• Capacity: 30+1 rounds 
• Safety: Lever safety mechanism 
• Grip Material: Black Polymer 
• Sights: Optic Ready 
• Condition: New in Box 
• Manufacturer Part Number (MPN): 30AC278TNG 
   

Detailed Features 

The 10.5" barrel keeps the package short and manageable while still producing useful ballistics with .300 Blackout, especially with heavier subsonic loads. With 30+1 rounds on tap, you have plenty of capacity for extended range sessions without constant reloads. The optic-ready setup means you can mount whatever sight system you prefer without needing an adapter. The lever safety is straightforward and positive in operation. 
 

Usage Scenarios 

The .300 Blackout caliber is genuinely flexible here. With supersonic loads it hits harder than 5.56 at close to medium ranges; switch to subsonic with a suppressor and it gets very quiet. That flexibility is the main reason shooters choose this chambering over standard 5.56 AR pistols. The compact size also works for home defense and makes it easy to store and maneuver in tight spaces.

Feedback on the CMMG Dissent MK4 in .300 Blackout with the tungsten finish covers several consistent themes.

Build quality gets positive marks across the board. The tungsten finish looks good and holds up well. Owners describe the overall construction as solid, and the controls are easy to reach and operate. The weight distribution gets mentioned positively, particularly for an AR-style pistol in this size class.

Performance with .300 Blackout is generally well-received. Users appreciate the caliber's versatility, especially those who run it suppressed with subsonic loads. Cycling is described as reliable across most ammo types.

Customization potential is a plus for platform enthusiasts. The optic-ready setup and standard AR parts compatibility mean you can build it out without hunting for proprietary components.

Price comes up as a point of contention. Some users feel the cost is justified given the quality and caliber, while others compare it to less expensive .300 Blackout options and question whether the premium is warranted. Customer service experiences with CMMG vary in reported accounts, though the warranty coverage is mentioned as a reassuring factor.