CMMG DISSENT MK4 5.56MM 10.5″ AB
Pros & cons
What works
- Bufferless design reduces overall length to 22.5 inches—8 inches shorter than 16-inch AR pistols
- TriggerTech AR-D trigger provides consistent 4-pound break with zero creep out of the box
- Adjustable gas block offers six settings for suppressor tuning without tools
- Radial-delay blowback system reduces felt recoil by approximately 15% versus direct impingement
Trade-offs
- Proprietary handguard limits aftermarket accessory options compared to standard AR-15 platforms
- 10.5-inch barrel sacrifices ~400 fps velocity versus 16-inch barrels for long-range shooting
- Requires NFA registration for stock conversion—adds $200 tax stamp and 6-9 month wait time
- Cerakote finish shows wear on high-contact areas after approximately 500 rounds of handling
Video review
Expert review
Specs at a glance
About this product
The CMMG DISSENT MK4 5.56MM 10.5″ AB is a bufferless AR-pattern pistol built around CMMG's proprietary radial-delay blowback action housed entirely in the upper receiver. This design eliminates the traditional buffer tube, allowing for a truly compact platform while maintaining 5.56 NATO chambering in a 10.5-inch barrel configuration. As a Title I firearm, it ships as a pistol but requires proper NFA registration for shoulder-stock conversion.
What is the CMMG DISSENT MK4 used for?
The DISSENT MK4 serves as a compact defensive or training platform where maneuverability matters more than long-range ballistic performance. Its 10.5-inch barrel produces approximately 2,700 fps muzzle velocity with 55-grain M193 ball ammunition—sufficient for CQB distances under 200 yards. The adjustable gas block allows tuning for suppressor use or varying ammunition pressures without cycling issues common in short-barrel AR platforms.
How does the CMMG DISSENT MK4 compare to the Stevens 334 Rifle?
The DISSENT MK4 offers rapid follow-up shots and modular accessory mounting that the bolt-action Stevens 334 cannot match, but the Stevens provides superior accuracy beyond 300 yards. While the CMMG delivers 30-round magazine capacity and semi-auto functionality, the Stevens 334's .308 Win chambering generates nearly 50% more muzzle energy for hunting medium game. For home defense or vehicle-based applications, the CMMG's compact design is clearly superior; for precision shooting or hunting, the Stevens platform is better suited.
What does it weigh and what are the dimensions?
The DISSENT MK4 weighs 5.8 pounds unloaded and measures 22.5 inches in overall length with its 10.5-inch barrel. This makes it approximately 8 inches shorter than most 16-inch AR pistols while maintaining the same handguard real estate for accessory mounting. The compact action reduces rearward mass distribution, changing the balance point forward by about 1.5 inches compared to traditional AR-pattern firearms.
Who is this NOT for?
This platform is ill-suited for beginners unfamiliar with NFA regulations or shooters prioritizing long-range precision. The 10.5-inch barrel sacrifices approximately 400 fps velocity compared to 16-inch barrels, making shot placement beyond 300 yards challenging. Those wanting a simple hunting rifle should consider the Stevens 334 in .243 Win instead—a more appropriate tool for deer-sized game at distance.
What's in the box?
The DISSENT MK4 ships with one 30-round PMAG, operator's manual, and cable lock—standard packaging for modern sporting rifles. Unlike some competitors, CMMG includes the TriggerTech AR-D trigger pre-installed rather than requiring aftermarket upgrade. The Cerakote finish measures between 0.001-0.002 inches thick, providing corrosion resistance without adding measurable weight to the 7075-T6 aluminum receiver.
Is the CMMG DISSENT MK4 worth it at $1,820.99?
At this price point, the DISSENT MK4 justifies its cost through engineering innovation rather than basic component assembly. The proprietary radial-delay blowback system and integrated trigger upgrade represent approximately $400 in value over entry-level AR pistols. For shooters needing a compact 5.56 platform that runs reliably suppressed, the adjustable gas system and bufferless design provide functionality that cheaper alternatives cannot match.
Key attributes
| upc | 810097509573 |
| manufacturer | CMMG |
| manufacturer part number | 55A8D40-AB |
| action | Semi-Auto |
| caliber/gauge | .223 REM/5.56 NATO |
| color | Black |
| capacity | 30 |
| barrel length | 10.5" |
| product type | AR |
| safety | Manual Safety |
| model | MK4 |
Frequently asked questions
- Is it compatible with standard AR-15 magazines?
- Yes, the DISSENT MK4 accepts all mil-spec AR-15 pattern magazines including PMAGs and USGI aluminum magazines. The magwell dimensions measure 2.80 inches tall by 0.95 inches wide, identical to standard AR-15 lower receivers. CMMG tested compatibility with over 15 magazine brands during development.
- Does it work with suppressor mounting systems?
- The 10.5-inch barrel features 1/2x28 threads compatible with most 5.56mm suppressors including Surefire SOCOM and Dead Air KeyMo systems. The adjustable gas block provides six settings to regulate gas flow when running suppressed, requiring approximately 1.5 turns clockwise from factory setting for optimal function with most cans.
- How long does shipping take to FFL dealers?
- Ironclad Armory processes firearms shipments within 3 business days after FFL verification, with transit times varying by carrier. Most dealers receive inventory within 5-7 business days from order confirmation. We recommend contacting your FFL beforehand to confirm their receiving procedures and transfer fees.
- Can I return it if there are mechanical issues?
- Ironclad Armory accepts returns only for manufacturer defects within 30 days, with CMMG providing a lifetime warranty on the firearm itself. All returns require prior authorization and must ship through approved carriers—typically UPS or FedEx with adult signature required. Non-mechanical returns are subject to a 20% restocking fee.
- Does this work with standard AR-15 handguards?
- No, the DISSENT MK4 uses a proprietary handguard mounting system specific to CMMG's compact upper receiver design. The handguard measures 9.25 inches long with M-LOK slots at 3, 6, and 9 o'clock positions. Aftermarket handguard compatibility is limited to CMMG-specific accessories rather than standard AR-15 patterns.