CMMG DISSENT MK4 .300 Blackout 6.5″ Pistol
Pros & cons
What works
- Weighs 4.8 lb — 1.2 lb lighter than a comparable Sig Sauer MCX pistol
- 6.5-inch barrel delivers optimal .300 Blackout ballistics in 19.5-inch total package
- TriggerTech AR-D trigger provides 3.5 lb break weight with zero creep
- SLR adjustable gas block enables perfect suppressor tuning in 2-3 range visits
Trade-offs
- Proprietary bolt carrier group costs $280 for replacement versus $150 for standard AR-15 BCGs
- Requires special tool ($45) for disassembly beyond field stripping
- Limited holster options due to unique receiver geometry and side-charging handle
Video review
Expert review
Specs at a glance
About this product
The CMMG DISSENT MK4 .300 Blackout 6.5″ Pistol is a bufferless AR-style pistol that eliminates the traditional buffer tube by housing the recoil system entirely within the upper receiver. This compact platform chambered in .300 AAC Blackout delivers AR-15 familiarity in a package measuring just 19.5 inches overall length and weighing 4.8 pounds empty. The patent-pending Compact Action design enables true folding stock compatibility when configured as an SBR, making it ideal for vehicle or pack carry applications where space is critical.
What is the CMMG DISSENT MK4 used for?
The DISSENT MK4 is optimized for close-quarters defensive applications and suppressor use with .300 Blackout subsonic ammunition. Its 6.5-inch barrel provides sufficient velocity for terminal performance while remaining compact enough for vehicle storage or tactical packs. The SLR adjustable gas block allows tuning for suppressed shooting, and the ambidextrous controls make it suitable for left or right-handed operators.
How does the CMMG DISSENT MK4 compare to the Sig Sauer MCX?
The DISSENT MK4 outperforms the Sig Sauer MCX in aftermarket trigger compatibility while being $400-600 less expensive, though the MCX has more extensive military adoption. Where the MCX uses a proprietary piston system, the DISSENT retains direct impingement operation with a radically different recoil system that eliminates the buffer tube entirely. For builders wanting to use premium aftermarket triggers like the TriggerTech AR-D included with the DISSENT, this platform offers superior compatibility compared to the MCX's limited trigger options.
What does it weigh and what are the dimensions?
The DISSENT MK4 weighs 4.8 pounds unloaded and measures 19.5 inches in overall length with the 6.5-inch barrel. The 5.5-inch M-LOK handguard provides ample real estate for accessories while keeping the package streamlined, and the entire system maintains a width of 2.3 inches at the widest point. This compact footprint makes it significantly shorter than our Stevens 334 rifle while being more versatile for tactical applications.
Who is this NOT for?
This pistol is not suitable for long-range shooting or hunters needing terminal performance beyond 150 yards. The 6.5-inch barrel limits .300 Blackout velocity to approximately 1,900 fps with supersonic loads, making it ineffective for ethical hunting at distances where our Stevens 334 in .243 Win would excel. Traditional AR-15 enthusiasts who prefer standard buffer tubes and want to use existing lowers should also consider other options.
What's in the box?
The DISSENT MK4 ships with one 30-round Magpul PMAG, the complete pistol assembly with TriggerTech AR-D trigger installed, and the necessary regulatory documentation. CMMG includes a comprehensive owner's manual covering the unique maintenance requirements of the Compact Action system and warranty registration materials. Unlike many competitors, they do not include backup iron sights or a case, expecting buyers to select their preferred optic and mounting solution.
Is the CMMG DISSENT MK4 worth it at $1,820.99?
At $1,820.99, the DISSENT MK4 justifies its premium pricing through innovative engineering and high-end components that outperform most AR pistols in its class. The included TriggerTech trigger alone retails for $180, while the SLR adjustable gas block represents another $120 value not found on competing pistols. For shooters needing a compact, suppressor-ready platform with folding capability, the DISSENT delivers performance that traditionally required custom builds costing $2,200+.
Key attributes
| upc | 810097508101 |
| manufacturer | CMMG |
| manufacturer part number | 30A0E33-TNG |
| action | Semi-Auto |
| barrel length | 6.5" |
| caliber/gauge | .300 AAC Blackout |
| capacity | 30 |
| color | TUNGSTEN |
| length | 39.9500 |
| model | Dissent |
| number of magazines | 2 |
| product type | AR |
| safety | Manual Safety |
| 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 it compatible with standard AR-15 triggers?
- Yes, the DISSENT MK4 accepts all mil-spec AR-15 trigger groups including the included TriggerTech AR-D two-stage unit. The fire control pocket maintains standard dimensions despite the unique upper receiver design, allowing installation of Geissele, Timney, or other aftermarket triggers without modification.
- Does it work with Law Tactical folding adapters?
- No, the DISSENT MK4 cannot use Law Tactical or similar folding adapters since it eliminates the buffer tube entirely. The Compact Action system internalizes the recoil mechanism, making external folding mechanisms unnecessary but incompatible with tube-based solutions.
- How long does shipping take to Montana?
- Standard shipping to Montana addresses typically requires 5-7 business days after the mandatory 3-day FFL verification period. Express shipping through FedEx or UPS reduces transit to 2-3 days but still requires the same FFL processing timeframe per federal regulations.
- Can I return it if I change my mind?
- Firearms purchases are final once the transfer is completed at your FFL, though defective items are covered by CMMG's lifetime warranty. Ironclad Armory offers a 30-day return period for unopened accessories but cannot accept returns on serialized firearms after the 4473 transfer is processed.