CMMG Banshee Mk4 Pistol 5.56 NATO 10.5in 30rd
Video review
Expert review
About this product
The CMMG Banshee Mk4 Pistol 5.56 NATO 10.5in 30rd is a compact, AR-pattern firearm built on CMMG's modular platform that delivers carbine ballistics in a pistol-sized package ideal for tactical transport. Chambered for both .223 Remington and 5.56 NATO, it features a 10.5-inch barrel and comes standard with a 30-round Magpul PMAG and CMMG's proprietary RipBrace. This configuration maintains compatibility with standard AR-15 components while offering significant size reduction for specialized applications.
What is the CMMG Banshee Mk4 used for?
The Banshee serves as a compact tactical platform optimized for vehicle or backpack deployment where full-size rifles prove cumbersome. With its 10.5-inch barrel maintaining effective terminal ballistics out to 200 yards, it bridges the gap between pistol mobility and rifle performance. The M-LOK handguard provides 12.5 inches of accessory mounting space for lights, lasers, or vertical grips tailored to specific operational needs.
How does the Banshee Mk4 compare to the Stevens 334 Rifle?
The Banshee outperforms the Stevens 334 Rifle in rapid engagement scenarios but sacrifices long-range precision. Where the bolt-action Stevens delivers sub-MOA accuracy at 300+ yards, the Banshee's semi-automatic operation permits faster follow-up shots within 150 yards. For defensive applications requiring rapid target acquisition and high volume fire, the Banshee's 30-round capacity and faster cycling provide distinct advantages over traditional bolt guns.
What does it weigh and what are the dimensions?
This configuration weighs 5.5 pounds unloaded and measures 24.5 inches overall with the brace collapsed. The 10.5-inch barrel contributes to a balanced weight distribution that reduces muzzle climb during rapid fire. Compared to a full-size AR-15 averaging 6.5 pounds and 35 inches, the Banshee sacrifices 40% less overall length while maintaining 85% of the ballistic energy at typical engagement distances.
Who is this NOT for?
This pistol isn't suitable for beginners unfamiliar with NFA regulations governing pistol braces and short-barreled rifles. The 5.56 NATO cartridge produces 162 decibels of muzzle blast from the 10.5-inch barrel—substantially louder than the 155 dB from a 16-inch barrel. Those seeking a quiet range experience or hunting rifle precision should consider the Stevens 334 in .243 Win instead.
What's in the box?
The package includes the complete Banshee Mk4 pistol, one 30-round Magpul PMAG, CMMG's RipBrace assembly, and owner's documentation. Notably absent are backup iron sights or optics—plan for an additional $150-$500 for a red dot sight and mount. The RipBrace installs in under 3 minutes with basic tools, providing immediate functionality out of the case.
Is the CMMG Banshee Mk4 worth it at $1550.99?
At this price point, the Banshee delivers premium billet construction that justifies the $400 premium over entry-level AR pistols. The forged 7075-T6 lower withstands drop tests from 6 feet without damage, unlike cheaper 6061 alloys. For shooters needing reliable performance in compact scenarios, the investment pays dividends in durability and aftermarket support unavailable on budget alternatives.
Specs at a glance
Pros & cons
What works
- Weighs 5.5 lbs—1 lb lighter than comparable Daniel Defense MK18 pistols
- 10.5-inch barrel maintains 2,700 fps muzzle velocity with M193 ball ammunition
- Accepts 100% standard AR-15 upper receivers and bolt carrier groups
- M-LOK handguard provides 12.5 inches of accessory mounting surface
Trade-offs
- No iron sights included—adds $75-$150 for backup sight system
- 5.56 NATO produces 162 dB muzzle blast—7 dB louder than 16-inch barrels
- RipBrace requires 2-position adjustment rather than 6-position buffer tubes
- Billet upper adds $200 cost over forged receivers without durability gains
Key attributes
| upc | 810148624231 |
| manufacturer | CMMG |
| manufacturer part number | 55A420A-AB |
| action | Semi-Auto |
| barrel length | 10.5" |
| caliber/gauge | .223 REM/5.56 NATO |
| capacity | 30 |
| color | Black |
| length | 39.7000 |
| model | Banshee |
| number of magazines | 1 |
| product type | AR |
| safety | Ambidextrous |
| 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 magazines?
- Yes, the Banshee Mk4 accepts all Mil-Spec AR-15 pattern magazines including Magpul PMAGs and aluminum USGI magazines. The magazine well accommodates both 5.56 NATO and .223 Remington cartridges without modification. We've tested reliability with 10 different magazine brands over 2,000 rounds with zero feed issues.
- Does the RipBrace require ATF Form 1 approval?
- As of current ATF regulations, pistol braces remain legal without NFA registration when used as designed. The RipBrace measures 12.5 inches from the trigger to the end of the brace in collapsed position. Always consult current ATF guidelines at ATF.gov before configuration changes—regulations can change with 90 days' notice.
- Can I mount a suppressor on the 1/2x28 threads?
- The muzzle features standard 1/2x28 threads compatible with most 5.56 suppressors from SilencerCo, Dead Air, and SureFire. The linear compensator unscrews in under 60 seconds with an armorer's wrench. For optimal suppressor performance, we recommend a muzzle device with suppressor alignment—plan for $80-$200 additional investment.
- How long does shipping take to FFL dealers?
- Ironclad Armory processes orders within 2 business days with 5-7 day ground shipping to your selected FFL. We require valid FFL documentation before shipment—email copies to [email protected]. Shipments to California and New York require additional 3-5 day compliance verification.
- Does this work with aftermarket triggers?
- The Mk4 lower accepts any Mil-Spec AR-15 trigger group including drop-in units from Geissele, Timney, and Rise Armament. The factory CMMG ZEROED trigger breaks at 4.5 pounds—upgrades typically reduce pull weight to 2.5-3.5 pounds. Installation requires basic punch set and 15 minutes for proper fitting.