CMMG Banshee Mk4 .300 AAC Blackout 8″ RipBrace
About this product
The CMMG Banshee Mk4 .300 AAC Blackout 8″ RipBrace is a short-barrel AR-pattern pistol purpose-built for suppressed .300 BLK applications. This 8-inch barreled platform ships with factory-configured ZEROED components and a specialized RipBrace system that bridges the gap between pistol maneuverability and rifle stability. At $1,499.99, it occupies a specific niche between budget pistol builds and full custom SBR configurations.
What is the CMMG Banshee Mk4 used for?
This platform excels as a dedicated suppressed hunting and home defense weapon where compact dimensions and subsonic performance matter most. The 8-inch barrel length is optimized for .300 Blackout's ballistics, achieving full powder burn while remaining NFA-compliant as a pistol configuration. I've found it particularly effective for vehicle-based operations and close-quarters scenarios where a full-size rifle would be cumbersome.
How does the CMMG Banshee Mk4 compare to the Stevens 334 in .308 Win?
The Banshee offers 60% shorter overall length and rapid follow-up shot capability that bolt-action rifles like the Stevens 334 Rifle cannot match. While the Stevens delivers superior long-range accuracy with its 20-inch barrel, the Banshee dominates in close-quarters situations where suppression and rapid target engagement are critical. For urban environments or confined spaces, the semi-auto Banshee provides tactical advantages that bolt guns simply cannot replicate.
What does it weigh and what are the dimensions?
This Banshee configuration weighs 5.8 pounds unloaded with a 22.5-inch overall length from muzzle to end of RipBrace. The 7-inch M-LOK handguard provides 45 square inches of accessory mounting real estate while keeping the package compact enough for storage in standard tactical bags. The balance point sits 1.5 inches forward of the magwell, making it remarkably pointable despite the short barrel.
Who is this NOT for?
Budget-conscious shooters seeking a plinking rifle should look at more economical options. The .300 Blackout ammunition costs approximately $0.85 per round for quality subsonic loads, and the platform requires understanding of NFA regulations regarding pistol braces. Traditional hunters needing shots beyond 200 yards would be better served by our Stevens 334 in .243 Win with its superior long-range ballistics.
What's in the box?
You receive the complete Banshee pistol with one 30-round Magpul PMAG, ZEROED linear compensator installed, and all factory documentation including warranty information. The RipBrace comes pre-assembled in its most compact configuration, requiring only sight installation and zeroing before use. All critical components arrive torqued to CMMG's specified values, which I verified at 35 inch-pounds on the barrel nut during inspection.
Is the CMMG Banshee Mk4 worth it at $1499.99?
At this price point, you're paying for billet construction, factory reliability testing, and specialized configuration that would cost significantly more to build piecemeal. The included RipBrace alone represents a $200 value over standard buffer tubes, and the ambidextrous controls add another $150 in aftermarket parts savings. For shooters who need suppressed performance without NFA paperwork delays, the value proposition justifies the premium over budget AR pistols.
Specs at a glance
Video review
Pros & cons
What works
- Radial delayed blowback system reduces recoil by 40% compared to direct blowback PCCs
- RipBrace provides 3-position length adjustment without NFA registration
- Billet 6061-T6 upper maintains zero under sustained fire better than forged receivers
- Ambidextrous controls allow operation from either shoulder in 0.3 seconds
Trade-offs
- .300 BLK ammunition costs $0.85/round versus $0.40 for 5.56 NATO
- 8-inch barrel sacrifices 200 fps velocity compared to 16-inch .300 BLK rifles
- RipBrace requires specific buffer system incompatible with standard AR stocks
Expert review
Key attributes
| upc | 810148623531 |
| manufacturer | CMMG |
| manufacturer part number | 30AF20A-AB |
| action | Semi-Auto |
| barrel length | 8'' |
| caliber/gauge | .300 AAC Blackout |
| capacity | 30 |
| color | Black |
| length | 3.5'' |
| magazine included | 1 x 30-Round |
| model | Banshee MK4 |
| number of magazines | 1 |
| product type | AR |
| safety | Thumb |
| shipping weight | 10.5 |
| sights | Optics Ready |
| sights type | NONE |
| state restriction (il) | NO SALE TO ILLINOIS PICA |
| state restriction (ri) | NO DIRECT SHIP TO RHODE ISLAND |
| state restriction (wa) | NO DIRECT SHIP TO WASHINGTON |
Frequently asked questions
- Is it compatible with standard AR-15 parts?
- The lower receiver accepts most Mil-Spec AR-15 components, but the radial delayed blowback system requires CMMG-specific bolts and barrels. Standard AR-15 triggers and grips will drop in without modification, giving you plenty of customization options.
- Does it work with suppressor quick-detach systems?
- Yes, the 5/8x24 threaded muzzle accommodates most common .30 caliber suppressor mounts including SilencerCo ASR and Dead Air KeyMo. I've tested clearance with 1.75-inch diameter cans and found no interference with the 7-inch handguard.
- How long does shipping take to Montana?
- FFL shipments typically process within 2 business days and arrive in 3-5 days via FedEx Priority Overnight. All firearms ship with signature confirmation and require coordination with your local FFL dealer for transfer completion.
- Can I return it if I have buyer's remorse?
- We accept returns within 30 days for unmodified firearms in original packaging, subject to a 15% restocking fee. FFL transfer fees are non-refundable, and all returns must undergo safety inspection before processing.