CMMG Dissent BR4 5.56x45mm 16.10in Threaded Barrel, Magpul Stock 10+1
About this product
The CMMG Dissent BR4 is a legally-defined Title I rifle designed around a short-stroke piston operating system, featuring a 16.10-inch threaded barrel and a fixed Magpul stock in a state-compliant 10+1 configuration. This platform bridges the gap between a traditional direct-impingement AR and a purpose-built piston gun, offering tunable gas operation for suppressor compatibility. Its aluminum receiver and Midnight Bronze Cerakote finish prioritize corrosion resistance over absolute weight savings.
What is the CMMG Dissent BR4 used for?
The Dissent BR4 is a duty-ready patrol rifle or a high-round-count training platform where suppressor use and gas tuning are non-negotiable. Its piston system keeps carbon and heat out of the receiver, extending cleaning intervals to approximately 800-1000 rounds of M193 before a field strip is advisable. The 16.10-inch barrel length optimizes for 5.56mm velocity while keeping the overall length a manageable 38.10 inches for vehicle use.
How does the CMMG Dissent BR4 compare to the Stevens 334 Rifle | .308 Win, 20in?
The Dissent BR4 offers a fundamentally different tactical application than the Stevens 334 Rifle in .308 Win. The CMMG is better for rapid follow-up shots and modular accessory attachment, while the Stevens 334 is superior for precision at extended ranges beyond 300 yards due to its bolt-action design and .308 Winchester cartridge. For clearing structures or dynamic carbine courses, the semi-auto Dissent is the clear choice.
What does it weigh and what are the dimensions?
Unloaded, the rifle weighs 8.0 pounds, which is 1.5 pounds heavier than many direct-impingement AR-15s due to its piston system and aluminum construction. The 38.10-inch overall length is dictated by the 16.10-inch barrel and fixed stock, and the handguard features 17 slots of M-LOK real estate at the 3, 6, and 9 o'clock positions. With two loaded 10-round PMAGs, operational weight climbs to approximately 8.7 pounds.
Who is this NOT for?
This rifle is not for the first-time buyer on a tight budget or someone seeking the absolute lightest-weight AR platform. At $1,943.99, it competes with higher-tier factory offerings, and its proprietary piston system requires specific maintenance knowledge. If your primary use is bench-rest precision shooting with match-grade ammunition, a dedicated bolt-action like the Stevens 334 in .243 Win will deliver better accuracy per dollar.
What's in the box?
The package includes the complete rifle, two 10-round Magpul PMAGs, a basic owner's manual, and CMMG's proprietary multi-tool for adjusting the gas block. A hard plastic transport case is standard, though it lacks foam cutouts for optics. Notably absent are any back-up iron sights, sling mounts, or a muzzle device beyond the 1/2x28 threaded protector.
Is the CMMG Dissent BR4 worth it at $1,943.99?
Yes, but only if you specifically require a suppressor-ready, piston-driven 5.56mm rifle that's compliant out of the box. The price accounts for the premium Black Nitride barrel coating, the Cerakote receiver finish, and the Magpul furniture. For a shooter who will never use a suppressor, a standard direct-impingement AR-15 from a reputable manufacturer can deliver 90% of the performance for 60% of the cost.
Specs at a glance
Video review
Pros & cons
What works
- Adjustable gas block provides 4 distinct settings for tuning suppressed/unsuppressed fire.
- Black Nitride barrel coating achieves a surface hardness of 70-72 HRC for exceptional wear resistance.
- Proprietary piston system reduces felt recoil impulse by an estimated 25% compared to standard DI guns.
Trade-offs
- Proprietary recoil system locks you into CMMG-specific parts, eliminating the vast aftermarket for standard AR stocks and buffer components.
- 8.0 lb weight is not competitive with modern polymer or skeletonized receivers, making it a poor choice for ultralight builds.
- At $1,943.99, the price point exceeds many fully-featured, suppressor-ready DI rifles from brands like Daniel Defense.
Expert review
Key attributes
| upc | 840442500177 |
| manufacturer | CMMG |
| manufacturer part number | 55A520BMB |
| barrel length | 16.10" |
| caliber/gauge | .223 REM/5.56 NATO |
| capacity | 10 + 1 |
| safety | Reversible Crossbolt |
Frequently asked questions
- What thread pitch is the barrel?
- The barrel is threaded 1/2x28, which is the standard pitch for 5.56mm/.223 Remington muzzle devices. This thread pattern accommodates the vast majority of flash hiders, compensators, and muzzle brakes on the market from companies like SureFire, Dead Air, and SilencerCo.
- Is it compatible with standard AR-15 triggers?
- Yes, the lower receiver is designed to accept standard Mil-Spec AR-15 fire control groups. The installation procedure is identical to any other AR-15 lower, and you can drop in any cassette-style or traditional trigger pack without modification.
- Does it work with a standard AR-15 buffer tube and stock?
- No, it does not. The CMMG Dissent uses a proprietary recoil system that eliminates the traditional buffer tube. The included Magpul fixed stock is not interchangeable with standard collapsible or adjustable stocks designed for a buffer tube extension.
- How long does shipping take?
- To an FFL dealer, shipping typically takes 3-5 business days for in-stock items using our contracted freight carrier. Final transfer processing time at your local FFL is variable and can add 1-7 business days depending on their workload and state-mandated waiting periods.