The CMMG Dissent AR MK4 is a 5.56x45mm NATO pistol with a 6.5-inch barrel, finished in Midnight Bronze. At 4.6 lbs, it's one of the lighter AR pistols in its class, and it ships with two 30-round magazines. 
 

Key Specifications 

• Make: CMMG 
• Model: Dissent AR 
• Action: Semi-Automatic 
• Caliber: 5.56x45mm NATO 
• Barrel Length: 6.5 inches 
• Capacity: 30 rounds (plus one in the chamber) 
• Finish: Midnight Bronze 
• Weight: 4.6 lbs 
   

Detailed Features 

 
The Dissent runs CMMG's proprietary Radial Delayed Blowback operating system rather than a standard direct impingement or piston setup. The radial delay reduces bolt carrier velocity at the moment of extraction, which cuts felt recoil and can improve reliability with a wider range of 5.56 loads. Controls are ambidextrous on the safety, and the receiver is optic-ready. The 6.5-inch barrel configuration means this is a pistol under federal law: an SB-style brace or pistol configuration only, no shoulder stock without the appropriate tax stamp.

Owners of the CMMG Dissent AR MK4 in 5.56 NATO with the 6.5-inch barrel are generally positive, with a few consistent criticisms.

The compact form factor draws praise. It's easy to maneuver and the 4.6-lb weight is genuinely light for a 5.56 pistol. Build quality gets good marks; the fit and finish are solid and the Midnight Bronze finish holds up well. On the range, users report manageable recoil for the caliber and barrel length, which they attribute to CMMG's Radial Delayed Blowback system. The design elements also get attention for looking distinct from standard AR pistols.

The criticisms: price is the main friction point, with many buyers noting it costs more than comparable AR pistols and questioning whether the operating system justifies the premium. A handful of users report occasional cycling or feeding hiccups with certain ammunition, particularly lighter loads. Accessory compatibility is another minor complaint. Some aftermarket parts that fit standard AR lowers don't work without modification. New AR pistol shooters also note the platform takes some adjustment if they're coming from traditional handguns.