CMMG Dissent Mk4 Pistol – .300 AAC Blackout, 6.5″
Video review
Expert review
About this product
The CMMG Dissent Mk4 Pistol in .300 AAC Blackout with a 6.5-inch barrel is a bufferless AR-style pistol engineered for suppressor-optimized, close-quarters personal defense. CMMG’s patent-pending Compact Action houses the recoil system entirely within the forged 7075-T6 aluminum upper receiver, eliminating the need for a buffer tube or stock to achieve a collapsed overall length of 14.7 inches. This creates a platform with AR-15 ergonomics and mounting compatibility, but in a profile that’s fundamentally rethought for discreet storage and rapid deployment.
What is the CMMG Dissent Mk4 Pistol used for?
This pistol is built primarily as a suppressor-ready, compact personal defense weapon for home or vehicle use. With its 6.5-inch barrel, it maximizes .300 Blackout's subsonic performance when paired with a suppressor, keeping the entire system exceptionally short. It balances a 14.7-inch collapsed length with ambidextrous controls, making it suitable for tight spaces and right- or left-handed users who need an immediate-use tool rather than a traditional carbine.
How does the CMMG Dissent compare to a Stevens 334 Rifle?
The Dissent is superior for close-quarters maneuverability and suppressor use, while the Stevens 334 Rifle is far better for precise, longer-range shooting. At 14.7 inches long and 4.75 pounds, the Dissent is built for speed and concealment inside a vehicle or by a bedside. In contrast, the Stevens 334 in .308 Win, with its 20-inch barrel, is a dedicated hunting or target rifle designed for accuracy at several hundred yards, making these two platforms solve completely different problems.
What does it weigh and what are the dimensions?
The pistol weighs 76 ounces (4.75 pounds) and measures 14.7 inches in overall length. The 6.5-inch, 1:7 twist barrel is paired with a 5.5-inch free-float M-LOK handguard, providing a minimal, accessory-ready forward section. The 5/8x24 threaded muzzle comes with CMMG's Zeroed linear compensator pre-installed, adding approximately 2.2 inches to the forward length unless replaced with a suppressor or other muzzle device.
Who is this NOT for?
This pistol is not for a first-time firearm owner or someone seeking a low-cost plinker. The .300 AAC Blackout round is more expensive than 5.56 NATO, and the platform's bufferless design, while innovative, departs from the standardized parts and troubleshooting knowledge of a traditional AR-15. It's also a poor choice for someone wanting to build a long-range Precision Rifle Series (PRS) competition rig; for that discipline, a bolt-action like the Stevens 334 in .243 Win is a more appropriate starting point.
What's in the box?
The package includes the complete Dissent Mk4 pistol, two 30-round Magpul PMAGs specifically designed for .300 Blackout, CMMG's Zeroed linear muzzle device, and a single Magpul MS4 Dual QD Sling. You will also find the operator's manual, a chamber safety flag, and a warranty registration card. Notably, it does not include iron sights, an optic, or a suppressor, which are considered essential add-ons for a functional defensive system.
Is the CMMG Dissent worth it at $1798.99?
At this price point, the Dissent is worth it for the user who specifically requires its unique combination of ultra-compact size, AR controls, and bufferless reliability. You are paying a premium for CMMG's engineered Compact Action system and the high-quality materials like the forged receiver and Cerakote finish. If your need is simply for a .300 Blackout firearm and a standard AR pistol with a brace tube would suffice, you can find capable options for $300-$500 less.
Specs at a glance
Pros & cons
What works
- Collapsed length of 14.7 inches — over 10 inches shorter than a standard 16-inch carbine with its stock collapsed.
- Weighs 76 oz (4.75 lbs) — balances compactness with a solid, shootable heft.
- Ambidextrous non-reciprocating side charger — can be configured for left or right-hand operation in under 2 minutes with an Allen wrench.
Trade-offs
- Proprietary Compact Action — limits aftermarket bolt carrier group options and increases potential repair complexity versus a mil-spec AR.
- No sights included — adds a minimum of $80-$150 for a set of quality backup iron sights.
- .300 Blackout ammunition cost — averages $0.80-$1.20 per round for supersonic, roughly double the cost of comparable 5.56 NATO.
Key attributes
| upc | 810097508040 |
| manufacturer | CMMG |
| manufacturer part number | 30A0E33AB |
| action | Semi-Auto |
| barrel length | 6.50" |
| caliber/gauge | .300 AAC Blackout |
| capacity | 30 + 1 |
| color | Black |
| length | 39.6000 |
| model | Dissent |
| number of magazines | 2 |
| product type | AR |
| safety | Ambidextrous |
| shipping weight | 7.8 |
| sights | Optic Ready |
| sights type | NONE |
| state restriction (il) | NO SALE TO ILLINOIS PICA |
| state restriction (or) | NO SALE TO OREGON |
| state restriction (ri) | NO DIRECT SHIP TO RHODE ISLAND |
| state restriction (wa) | NO DIRECT SHIP TO WASHINGTON |
Frequently asked questions
- Is the Dissent compatible with standard AR-15 parts?
- Upper receiver compatibility is limited; it uses CMMG's proprietary Compact Action, so standard AR-15 bolt carrier groups and buffer systems will not work. However, it uses a standard AR-15 fire control group (trigger, hammer, disconnector), and the lower receiver accepts most AR-15 grips, triggers, and safety selectors. The handguard uses a standard M-LOK attachment system for accessories.
- What suppressor thread pitch does it have?
- The barrel is threaded 5/8x24, which is the standard thread pitch for .30 caliber barrels, including those chambered in .300 AAC Blackout and .308 Winchester. This allows direct attachment of most .30 caliber suppressors without an adapter. The included CMMG Zeroed linear comp is also 5/8x24 threaded.
- Does it ship as a pistol or a firearm?
- It ships from our facility as a completed pistol, transferred on a Form 4473 as a 'Firearm.' It is not classified as a Title II Short-Barreled Rifle (SBR) in its factory configuration. Please consult your local and state laws regarding pistol ownership and any potential restrictions on configuration, such as adding a vertical foregrip, which would change its legal classification.
- How long does shipping take to an FFL?
- Processing at Ironclad Armory takes 1-2 business days after order verification and payment clearance. Transit time via our partnered carrier to your selected FFL dealer is typically 3-5 business days for the continental United States. You will receive tracking information via email once the shipment is scanned into the carrier's system.