The CMMG Dissent MK4 is a semi-automatic pistol chambered in .300 AAC Blackout, with a 6.5-inch barrel and 30+1 round capacity. At 4.6 lbs, it handles reasonably well for its caliber. The Midnight Bronze finish looks good in person. Ambidextrous safety and an optic-ready configuration round out a package that works for home defense or range use without being too bulky to carry. 
 

Key Specifications 

• Model: Dissent MK4 
• Caliber: .300 AAC Blackout 
• Action: Semi-Automatic 
• Barrel Length: 6.5 inches 
• Capacity: 30+1 rounds 
• Weight: 4.6 lbs 
• Finish: Midnight Bronze 
• Safety Feature: Ambidextrous 
• Sights: Optic Ready 
   

Features 

The semi-automatic action keeps follow-up shots quick and recoil manageable. The optic-ready design accepts a wide range of sights, so you can run whatever system fits your shooting style. Ambidextrous safety makes it usable left- or right-handed without modification. At 4.6 lbs the pistol is light enough for extended range sessions, though the .300 BLK out of a short barrel does have some bark to it.

Owners of the CMMG Dissent MK4 6.5" .300 BLK in Midnight Bronze tend to land somewhere between genuinely impressed and constructively critical.

On the positive side, the compact build and 4.6 lb weight get consistent praise for maneuverability. The Midnight Bronze finish draws attention at the range. Most shooters report good reliability across a variety of .300 BLK loads, and the cartridge's ability to run both subsonic and supersonic ammunition is a recurring selling point.

On the critical side, price comes up often. The Dissent costs more than several AR-pistol alternatives, and not everyone feels the premium is fully justified. Shooters new to short-barreled .300 BLK sometimes find the recoil snappier than expected. There are also occasional debates about parts compatibility with standard AR platforms, since not all components interchange directly.

The overall conversation balances appreciation for the design and caliber flexibility against practical questions about price and handling for less experienced shooters.