CMMG Banshee MK4 Pistol .300 Blackout 8in Bronze
About this product
What is the CMMG Banshee MK4 Pistol .300 Blackout 8in Bronze? It’s a purpose-built AR-pattern pistol designed specifically for optimized suppressed .300 AAC Blackout performance in a compact, legally compliant package. Unlike a typical rifle, this 8-inch barreled pistol uses the CMMG RipBrace system to remain NFA-unregulated while providing a stable, adaptable platform for close-quarters use or discreet transport. Its entire component selection—from the ZEROED trigger group to the EML7 handguard—targets reliability and precision under the unique pressures and velocities generated by subsonic and supersonic .300 BLK rounds fired through suppressors or short barrels.
What is the CMMG Banshee MK4 used for?
This platform is engineered for discrete, close-quarters defensive applications and optimized suppressed recreational shooting. It's designed to perform properly with both 110-125 grain supersonic and 190-220 grain subsonic .300 Blackout ammunition from an 8-inch barrel, which is the minimum effective length for reliable cycling with heavy subs. You won't find this level of attention to gas port sizing and buffer weight on a generic 5.56 pistol—this is a purpose-built tool, not a converted carbine.
How does the CMMG Banshee MK4 compare to the Stevens 334 Rifle?
The Banshee MK4 is fundamentally a close-quarters, rapid-engagement system, while the Stevens 334 Rifle is a bolt-action precision tool for distance. The Stevens in .308 Winchester delivers superior long-range accuracy from a 20-inch barrel (sub-MOA potential), but weighs approximately 2.3 lbs more and has far slower follow-up shot capability. For home defense or vehicle-based scenarios where compact size and rapid, controlled firepower matter more than 400-yard precision, the Banshee’s semi-automatic action and pistol configuration are objectively superior.
What does it weigh and what are the dimensions?
The Banshee MK4 has an empty weight of 5.8 lbs, an overall length of 23.75 inches with the RipBrace collapsed, and a height of 7.5 inches from rail top to magwell base. Collapsed, it fits easily in a standard 24-inch rifle case or a discreet backpack; extended, the length of pull adjusts from approximately 9 inches to 13.5 inches. When paired with a 7-inch suppressor, total length increases to roughly 30 inches, still shorter than most 16-inch carbines without a can.
Who is this NOT for?
Avoid this if your primary use case is unsuppressed shooting with exclusively supersonic ammunition, or if you require a true stock for competition use. The .300 Blackout round burns most of its powder within 9 inches, but supersonic loads are significantly louder and produce a substantial muzzle flash from an 8-inch barrel without a suppressor—this negates the cartridge's primary advantage. Additionally, if you intend to immediately Form 1 this into an SBR and attach a vertical foregrip, you’re paying for the RipBrace system you’ll discard.
What's in the box?
You receive the complete pistol, one 30-round PMAG, the CMMG ZEROED linear compensator installed, a quick-start guide, and the lockable hard case. Notably absent are backup iron sights, a sling, or any suppressor-specific mounting hardware—CMMG assumes you’re sourcing those based on your specific can and optic choice. The RipBrace includes the necessary tool for adjustment, but you’ll need your own Allen set for handguard accessory mounting.
Is the CMMG Banshee MK4 worth it at $1,506.99?
Yes, if your requirement is a turnkey, reliable .300 BLK pistol purpose-built for suppression from the ground up. The premium over a budget AR pistol (around $800) pays for the proprietary radial-delay blowback system that reduces felt recoil by approximately 30%, the matched ZEROED components ensuring consistent 4.5-lb trigger pull, and the correct gas system tuning out of the box. If you were to build a comparable pistol using similarly graded parts (FailZero BCG, Geissele trigger, BCM handguard), you'd exceed this price without the integrated system reliability testing.
Specs at a glance
Video review
Pros & cons
What works
- Radial-delay blowback system reduces felt recoil by approximately 30% compared to direct blowback .300 BLK pistols.
- Complete package weight of 5.8 lbs—1.2 lbs lighter than a comparable Daniel Defense DDM4 PDW with brace.
- 8-inch 4140CM SBN barrel with 1:7 twist stabilizes subsonic rounds down to 190 grains without keyholing.
- ZEROED trigger group provides a consistent 4.5-lb pull weight with minimal creep out of the box.
- Midnight Bronze Cerakote finish provides 500-hour salt spray corrosion resistance, exceeding standard anodizing.
Trade-offs
- Proprietary bolt carrier group and barrel extension limit aftermarket upgrades—replacement BCG costs $289 from CMMG only.
- RipBrace adjustment mechanism requires a proprietary tool; lose it and you're ordering from CMMG for $12.99 plus shipping.
- No iron sights included—adds $90-$250 for a backup sight system before you can zero.
- Linear compensator is excessively loud with supersonic ammo; plan $80-$120 for a muzzle brake or direct-thread suppressor mount.
Expert review
Key attributes
| upc | 810148623562 |
| manufacturer | CMMG |
| manufacturer part number | 30AF20AMB |
| action | Semi-Auto |
| barrel length | 8" |
| caliber/gauge | .300 AAC Blackout |
| capacity | 30 + 1 |
| color | BRONZE |
| length | 39.5500 |
| model | Banshee |
| number of magazines | 1 |
| product type | AR |
| safety | CMMG Zeroed 60/90 Degree |
| shipping weight | 10.0 |
| 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 and fire control group accept any mil-spec AR-15 trigger, grip, and safety selector. However, the upper uses CMMG's proprietary radial-delay blowback bolt carrier group and barrel extension—you cannot swap in a standard direct-impingement BCG or barrel. The handguard uses a proprietary barrel nut system but accepts any M-LOK accessories.
- Does it fit in a standard AR pistol case?
- Yes, with the RipBrace collapsed to its 23.75-inch length, it fits neatly in a 24-inch soft or hard AR pistol case. For transport with an optic and suppressor attached, you'll need a case with interior dimensions of at least 32 inches in length, such as a Pelican 1750.
- How long does shipping take to an FFL?
- Ironclad Armory processes and ships within 2 business days via UPS or FedEx with adult signature required. Transit time is typically 3-5 business days continental US, but FFL processing and your background check can add 1-10 days depending on local regulations.
- Can I return it if it doesn't cycle my ammunition?
- Returns on firearms are restricted to manufacturer defect only, per federal law. If you experience cycling issues, CMMG recommends a 500-round break-in period with 120-grain or heavier ammunition. Persistent issues require a warranty claim handled directly through CMMG, which has a 72-hour initial response time.
- Does this work with a SilencerCo Omega 300 suppressor?
- Yes, the 5/8x24 threaded muzzle accepts any .30 caliber suppressor with that thread pattern, including the Omega 300. You must first remove the factory-installed CMMG linear compensator using a 3/4-inch crowfoot wrench and proper vise blocks to avoid damaging the barrel.