CMMG Dissent MK4 5.56 NATO Rifle - 14.5" Barrel, Armor Black Finish

The CMMG Dissent MK4 5.56 NATO rifle delivers compact, modern AR functionality without the traditional buffer tube. Built on CMMG's Mk4 platform and chambered in 5.56x45mm, this 14.5" barrel rifle (pinned and welded to 16.1" to comply with federal length requirements) splits the difference between a short carbine and a pistol—giving you maneuverability in tight spaces without the registered firearm hassles. If you're running a tactical rifle setup, want a truck gun that doesn't eat up space, or need a home-defense AR that handles like something half its size, the Dissent MK4 is built for exactly that job.

The standout feature here is the bufferless Compact Action. CMMG ditched the buffer spring and tube entirely, replacing them with a 1913 Picatinny rail end cap that gives you rock-solid mounting for slings, lights, and folding braces. That design choice means less moving parts, less maintenance, and a cleaner receiver profile—and it cuts weight without compromising reliability. The reversible side-charging handle is another win: you can configure it left or right without breaking the ergonomics of your sight picture, and it stays put during shooting.

Under the hood, the Dissent MK4 runs a direct-impingement system with an adjustable 0.750" gas block, a 1:7 barrel twist in 4140CM steel, and a CMMG ZEROED SVD brake pinned to the muzzle. The forged 7075 T6 aluminum upper and lower receivers are rock-solid, paired with a proprietary 13.5" hand guard and CMMG's ZEROED drop-in trigger. Everything groups around shooter-friendly ergonomics: ambidextrous safety lever, reversible charging handle, and a well-designed pistol grip. It ships with two 30-round Magpul PMAGs and weighs just 6.2 lbs—light enough to maneuver, heavy enough to stay controllable. The Armor Black Cerakote finish handles field use without flinching.

If you want an AR that thinks smaller but hits like a rifle, or you need something that transitions smoothly between tight drills and open-range work, the Dissent MK4 is engineered to fit that slot.

Key Features

• Bufferless Compact Action design with Picatinny rail end cap for simpler maintenance and accessory compatibility
• Reversible side-charging handle—configure left or right without interrupting your sight line
• 14.5" barrel pinned and welded to 16.1" for compliance and maneuverability
• Direct-impingement system with adjustable gas block for tuning and reliability
• Forged 7075 T6 aluminum receivers for durability and lightweight handling
• CMMG ZEROED drop-in trigger and ergonomic controls for smooth, intuitive shooting
• Includes two 30-round Magpul PMAGs and CMMG ZEROED SVD brake
• Armor Black Cerakote finish resists corrosion in field conditions
• Weighs 6.2 lbs for compact maneuverability

Specifications

Frequently Asked Questions

What makes the Dissent MK4 different from a standard AR-15?

The Dissent MK4 replaces the traditional buffer tube and spring with a bufferless Compact Action system. This removes reciprocating mass, reduces part count, and lets you mount a Picatinny rail end cap in place of a buffer tube—opening up options for slings, lights, and folding braces. It also uses a reversible side-charging handle instead of a rear charging handle, so you can keep your shooting grip stable while chambering rounds.

Can I use standard AR-15 magazines with the Dissent MK4?

Yes. The Dissent MK4 is chambered in 5.56x45mm NATO and accepts standard AR-pattern magazines. It ships with two 30-round Magpul PMAGs.

What's included in the box?

The rifle comes with two 30-round Magpul PMAGs and the CMMG ZEROED SVD brake (already pinned and welded to the muzzle).

Why is the barrel pinned and welded to 16.1 inches?

The 14.5" barrel is pinned and welded to a total length of 16.1" to comply with federal firearms regulations that require rifle barrels to be at least 16 inches long. This gives you the ballistic and handling benefits of a short barrel within the legal framework for an unserialized rifle.