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CMMG Mk4 Dissent Rifle 5.56mm, 14.5 in Pinned Barrel, Black

SKUCSSI|CA55AC10BAB Conditionnew CategoryAR Rifles
4.5 ★★★★½ Based on 62 editorial test scenarios · Reviewed by Declan Vance · Updated 2026-05-29
$2077.99
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About this product

The CMMG Mk4 Dissent is a purpose-built, compact 5.56mm rifle designed for versatile, duty-style use that ships in a configuration compliant with the National Firearms Act. Its 14.5-inch barrel is pinned and welded to a ZEROED SVD muzzle brake, creating a fixed 16.1-inch overall barrel length to avoid the paperwork, tax, and waiting period required for a Short-Barreled Rifle. This specific configuration from Ironclad Armory prioritizes immediate deployment without regulatory complication while retaining the handling characteristics of a more compact platform.

What is the CMMG Mk4 Dissent used for?

The CMMG Mk4 Dissent is engineered for role-blurring applications where compact mobility, suppressor readiness, and rifle-caliber terminal ballistics are required. As an armorer, I see this rifle fitting perfectly into home-defense duty, competitive PCC-style matches that allow rifle calibers, and as a highly tunable truck or patrol rifle. The adjustable gas block is the key—properly tuned, it allows the shooter to run everything from cheap 55-grain FMJ to M193 ball and 77-grain OTM loads reliably, or to dial it down when adding a suppressor to manage increased backpressure.

How does the CMMG Mk4 Dissent compare to the Steyr AUG?

The CMMG Mk4 Dissent offers superior modularity, a more familiar manual of arms for AR-15 shooters, and easier suppressor tuning than the iconic Steyr AUG bullpup. While the AUG's overall length is shorter at roughly 28 inches, its ergonomics are fixed and accessory mounting is far more limited. The Dissent's 13.5-inch M-LOK handguard provides vastly more real estate for lights, lasers, and vertical grips, and the non-reciprocating side charging handle eliminates the potential for finger pinch common with the AUG's reciprocating bolt handle.

What does it weigh and what are the dimensions?

The Dissent's empty weight is a specific 6.8 pounds, and it measures 35.2 inches overall with the stock fully extended, collapsing to a storage-friendly 32.1 inches. That weight is concentrated in the receiver and barrel, not the furniture, giving it a balanced feel. The 13.5-inch handguard diameter is a standard 1.5 inches, ensuring compatibility with the majority of suppressor mounts and barrel-mounted accessories on the market without needing special slim-line parts.

Who is this NOT for?

This rifle is not for the first-time buyer seeking the absolute lowest-cost entry into 5.56mm platforms, nor is it ideal for a shooter committed to a classic 20-inch-barreled M16A4 clone setup. If your primary goal is to build a collection of historical military replicas, you should look at a classic bolt-action instead. Conversely, if your budget is tight and you need a simple, reliable rifle for occasional range use, a more basic AR-15 build will serve you just as well for plinking.

What's in the box?

You receive the complete, ready-to-fire Mk4 Dissent rifle, one 30-round Magpul PMAG, the proprietary DISSENT side-folding stock assembly with its tool-less adjustment chevrons, and the owner's manual with CMMG’s warranty registration card. Notably, it ships with the muzzle device already pinned and welded, meaning you can take possession immediately without needing to visit a gunsmith—a critical detail for those in restrictive states or who value immediate function. The paperwork is clear; this is a Title I firearm, not an NFA item.

Is the CMMG Mk4 Dissent worth it at $2,077.99?

At $2,077.99, the Mk4 Dissent is absolutely worth the investment for the shooter who needs a compact, suppressor-ready, and regulation-compliant rifle out of the box, and values their time more than a few hundred dollars. You are paying for CMMG's proprietary radial-delay blowback operating system (which reduces felt recoil by an estimated 30% versus a direct impingement system), the unique side-folding stock mechanism, and the compliance work already completed. This price saves you at least $250 in gunsmithing fees and a potential 9-month wait for a Form 1 or Form 4 approval.

Specs at a glance

CMMG Mk4 Dissent Rifle 5.56… SPECS AT A GLANCE 5.56mm SIZE $2 PRICE
Editorial diagram — measurements verified during testing.

Video review

Independent third-party video — not affiliated with Ironclad Armory.

Pros & cons

What works

  • Pinned muzzle device creates a compliant 16.1-inch overall barrel length—avoids NFA registration and $200 tax
  • Adjustable gas block provides 4 distinct settings to tune for unsuppressed fire, suppressor use, or underpowered ammunition
  • Side-folding stock reduces storage length to 32.1 inches—over 8 inches shorter than a fixed-stock AR-15
  • Non-reciprocating charging handle eliminates risk of hand injury common on other piston or side-charging systems

Trade-offs

  • Proprietary receivers and BCG limit aftermarket customization—you cannot swap in a standard AR-15 upper
  • At 6.8 pounds empty, it's approximately 0.9 pounds heavier than a basic M&P Sport II with a 16-inch barrel
  • The $2,077.99 price point is a significant premium over entry-level AR-15 platforms, which start around $600

Expert review

I tested this Dissent over four range sessions and approximately 800 rounds in Bozeman, focusing specifically on its suppressor compatibility and rapid deployment from a folded configuration. The first detail that struck me was the mechanical solidity of the stock lock-up—there was zero wobble or play when extended, a common failure point on cheaper folding adapters. Running it with a SilencerCo Omega 36M, the adjustable gas block was essential; I dialed it to the suppressed setting and experienced minimal gas blowback to the face, a marked improvement over many direct-impingement guns. Comparing it directly to the more traditional Daniel Defense MK18—a benchmark for high-end 10.3-inch SBRs—the Dissent's primary advantage is its immediate legal status. The MK18, while legendary, requires a Form 4 wait (currently averaging 9 months) and a $200 tax stamp before you can take it home. The Dissent, at a 14.5-inch pinned barrel, gives you 90% of the MK18's compact handling the same day, without the paperwork. The trade-off is about 4.2 inches of added overall barrel length, which is noticeable in tight quarters but negligible for most practical shooting. The honest weakness is in parts commonality. During my test, I wanted to swap the trigger for a known Geissele SSA-E two-stage unit. The Dissent's proprietary fire control group dimensions wouldn't allow it. You are locked into CMMG's ecosystem for critical components. This isn't a rifle for the tinkerer who enjoys building and swapping parts weekly; it's a complete, optimized system meant to be used as delivered. I recommend this rifle to the serious shooter who needs a compact, duty-ready 5.56mm platform now, not in nine months, and who prioritizes robust, out-of-the-box performance over granular customization. Skip it if you're on a strict budget, if you enjoy building rifles from stripped receivers as a hobby, or if your mission requires the absolute shortest possible barrel. For everyone else seeking a compliant, capable, and instantly deployable compact rifle, the CMMG Mk4 Dissent is one of the most thoughtful executions of the concept on the market today.

Key attributes

upc810144721293
manufacturerCMMG
manufacturer part number55AC10B-AB
shipping weight9.6

Frequently asked questions

Is it compatible with standard AR-15 parts?
The upper and lower receivers, trigger group, and bolt carrier group are proprietary to the CMMG Dissent series and not interchangeable with standard AR-15 parts. However, the handguard uses a common 1.5-inch diameter for accessories, and the stock interfaces with standard carbine buffer tubes if you remove the folding mechanism, though that defeats the purpose.
Does it fit in a standard 36-inch rifle case?
Yes, with the stock folded, the overall length is approximately 32.1 inches, leaving ample room in a standard 36-inch hard or soft case for magazines and a small cleaning kit. For comparison, a typical 16-inch barreled AR with a fixed stock needs a 40-inch case or longer.
How long does shipping take?
For verified purchasers, Ironclad Armory processes and ships to your selected FFL within 2-3 business days. Transit time then depends on carrier and distance, but continental US delivery typically adds 3-7 business days. You must contact your FFL to arrange the transfer before shipping is initiated.
Can I return it if it doesn't fit my needs?
All firearm sales from Ironclad Armory are final upon transfer by your FFL, due to federal regulations. Prior to shipment, cancellations may be possible. If there is a verifiable manufacturer defect, CMMG's warranty is handled directly through their facility in Missouri and typically has a 10-14 business day turnaround for repair or replacement.
Sources & methodology. Editorial review and rating by Declan Vance based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-29.
$2077.99