Experience a new level of compact power, modern ergonomics, and mission-ready design with the CMMG Dissent MK4 in 300 Blackout—a cutting-edge AR-platform firearm engineered for shooters who want maximum performance in a short, highly maneuverable package. Featuring a 10.50" barrel, a left side charging handle, Armor Black finish, a Zeroed Linear Comp, a 9.60" M-LOK handguard, and a Picatinny end plate, the CMMG Dissent MK4 300 Blackout (30BC239AB / UPC 810097509115) is built for fast handling, smooth control, and serious capability.
If you’re searching for a CMMG Dissent 300 Blackout, a 10.5 inch 300 BLK AR-platform, or a left side charging 300 Blackout firearm optimized for modern accessories, this is a standout option for home defense, range training, and compact tactical setups.
Built for the AR Platform—Reimagined for Modern Handling
The CMMG Dissent MK4 keeps the familiarity and modularity shooters love about the AR ecosystem while bringing a more streamlined, contemporary layout to the table. From the moment you shoulder it, the Dissent is designed for real-world usability—especially in tight spaces where traditional setups can feel bulky.
Whether you’re building a compact-ready system or want a modern AR-platform firearm that balances performance with portability, the Dissent MK4 is engineered with handling and control as top priorities.
300 Blackout: Compact Performance with Serious Versatility
Chambered in 300 Blackout, this platform is tailored for short-barrel performance and offers excellent versatility for a wide range of use cases. 300 BLK is widely favored for compact builds because it can deliver strong performance from shorter barrel lengths while maintaining excellent downrange capability for its class.
The result is a setup that’s well-suited for:
Compact defensive configurations
Range training and drills
Suppression-focused builds (where legal and applicable)
General-purpose use where maneuverability matters
10.50" Barrel: Maneuverable Size, Purpose-Driven Balance
The 10.50-inch barrel hits a sweet spot for shooters who want a compact footprint without giving up the feel and control of a substantial front end. Shorter systems can move faster between targets, clear corners more easily, and feel more responsive in confined environments—making this configuration an excellent choice for anyone prioritizing mobility.
This length is also ideal for shooters who want a balanced setup that supports modern accessories without becoming front-heavy.
Left Side Charging Handle: Faster Manipulation, Cleaner Ergonomics
One of the signature features of this model is the left side charging handle, which can be a major ergonomic upgrade for many shooters. A side charger can streamline administrative handling and make it easier to manipulate the action without breaking your grip or shifting your posture as much.
Benefits of a left side charging handle often include:
Easier manipulation while maintaining a firing grip
Quicker, more intuitive operation during drills
Improved handling with certain optic and accessory layouts
A modern control approach many shooters prefer on compact builds
For shooters who prioritize smooth weapon handling and rapid manipulation, the side-charging design is a major highlight of the Dissent platform.
Zeroed Linear Comp: Directed Blast for Better Practical Shooting
This configuration includes the Zeroed Linear Comp, designed to direct muzzle blast forward. Linear comps are popular on compact firearms because they help push concussion and blast away from the shooter and those nearby—especially noticeable on short-barrel setups.
That forward-directed blast can improve the overall shooting experience, particularly in:
Indoor range environments
Close-proximity training lanes
Compact setups where muzzle blast is more apparent
9.60" M-LOK Handguard: Accessory-Ready and Comfortable
The 9.60-inch M-LOK handguard gives you a sleek, modern mounting solution with plenty of flexibility. M-LOK has become the dominant standard for modular accessory attachment because it’s lightweight, secure, and adaptable—letting you place accessories where they make the most sense for your grip and shooting style.
With M-LOK, you can configure your setup with compatible accessories such as:
The 9.60" length pairs well with the 10.50" barrel, giving you useful hand placement and accessory real estate without unnecessary bulk.
Picatinny End Plate: Expandability for Modern Stocks and Braces
The included Picatinny end plate adds another layer of modularity to the platform, opening the door to a variety of Picatinny-compatible rear-end accessories and mounting solutions (subject to local laws and regulations). It’s a smart choice for shooters who want the flexibility to tailor the rear setup to their preferred configuration.
Armor Black Finish: Clean, Durable, Professional Look
Finished in Armor Black, this CMMG Dissent MK4 has a sleek, modern aesthetic that fits professional builds and holds up well across typical range and field use. A quality finish isn’t just about looks—it also supports durability, wear resistance, and long-term pride of ownership.
Why Choose the CMMG Dissent MK4 300 Blackout?
If you want a premium compact AR-platform firearm with modern controls and a highly configurable setup, this model checks the boxes that matter:
Compact and maneuverable 10.50" 300 Blackout configuration
Left side charging handle for streamlined handling
Zeroed Linear Comp to direct blast forward
9.60" M-LOK handguard for modular accessories
Picatinny end plate for expanded configuration options
Durable, clean Armor Black finish
It’s designed for shooters who don’t want generic—they want a platform that feels purpose-built for compact performance and modern accessory integration.
Product Identification for Easy Matching
Make sure you’re selecting the correct model with these identifiers:
Manufacturer: CMMG
Model: Dissent MK4
Caliber: 300 Blackout
Barrel Length: 10.50"
Charging Handle: Left Side Charging
Finish: Armor Black
Muzzle Device: Zeroed Linear Comp
Handguard: 9.60" M-LOK
Rear Interface: Picatinny End Plate
Platform Fit: AR-Platform
Part Number / SKU: 30BC239AB
UPC: 810097509115
The Bottom Line
The CMMG Dissent MK4 300 Blackout 10.50" is a compact, modern AR-platform solution designed to deliver premium handling, flexible accessory integration, and a refined feature set that stands out in the 300 BLK category. Whether you’re building a compact defensive setup, upgrading your training platform, or simply want a high-performance firearm with a left side charging handle and M-LOK modularity, this configuration brings the features and usability shooters demand today.
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