CMMG Banshee Mk4 9mm Pistol 5″ Threaded 30rd Tungsten
About this product
The CMMG Banshee Mk4 9mm Pistol is a compact AR-platform firearm chambered in 9mm with a 5-inch threaded barrel and 30-round capacity, built for short-range applications and suppressor compatibility. This configuration uses CMMG's proprietary radial delayed blowback system to reduce felt recoil while maintaining reliability with common ammunition. Its tungsten Cerakote finish provides corrosion resistance while the optics-ready upper receiver accepts most micro red dots.
What is the CMMG Banshee Mk4 used for?
The Banshee Mk4 excels as a compact defensive or range pistol, particularly when configured with a suppressor. The 5-inch barrel keeps overall length at 21.5 inches while maintaining reliable cycling with 115-147 grain ammunition. I've found it performs best with defensive hollow points and standard pressure rounds rather than +P loads.
How does the CMMG Banshee Mk4 compare to the Stevens 334 Rifle?
The Banshee offers quicker follow-up shots than the bolt-action Stevens 334 Rifle but sacrifices long-range precision. While the Stevens 334 in .308 Win delivers sub-MOA accuracy at 200 yards, the Banshee's effective range tops out at 75 yards with 9mm ballistics. Choose the Banshee for close-quarters speed; choose the Stevens for hunting precision.
What does it weigh and what are the dimensions?
Unloaded weight is 4.8 pounds with dimensions of 21.5 inches overall length and 7.5 inches height without optics. The 5-inch barrel contributes to the compact profile while the mil-spec buffer tube adds 7.25 inches to the rear. Balance point sits just forward of the magazine well, making it muzzle-light for rapid target transitions.
Who is this NOT for?
Avoid this platform if you require aftermarket magazine compatibility or live in states with capacity restrictions. The proprietary CMMG magazine system limits options to factory 30-round magazines only, unlike Glock-compatible PCC systems. The pistol brace configuration also creates NFA considerations if modifying to shoulder-fired operation.
What's in the box?
You receive the complete pistol, one 30-round CMMG magazine, and a thread protector for the 1/2x28 muzzle threads. Unlike some competitors, CMMG includes neither iron sights nor optic mounting hardware. Expect to add $150-400 for a quality red dot and mount before the pistol is range-ready.
Is the CMMG Banshee Mk4 worth it at $1623.99?
At this price point, you're paying for the radial delayed blowback system and CMMG's quality control rather than included accessories. Compared to direct-blowback 9mm AR pistols costing $800-1200, the Banshee's reduced recoil and smoother operation justify the premium for serious shooters. Consider the Stevens 555 Sporting Compact if you need a budget-friendly alternative for different applications.
Specs at a glance
Video review
Pros & cons
What works
- Radial delayed blowback reduces felt recoil by approximately 30% compared to direct blowback systems
- Weighs 4.8 pounds unloaded—1.2 pounds lighter than comparable 9mm PCC platforms
- 5-inch barrel maintains 1150 fps velocity with 124 grain ammunition
- Accepts all Mil-Spec AR-15 triggers and grips for customization
Trade-offs
- Proprietary magazines cost $35 each versus $20 for Glock-compatible alternatives
- No iron sights included—add $100-200 for quality backup sights
- Pistol brace may require Form 1 submission for shoulder firing under current ATF interpretations
- Cerakote finish shows holster wear more visibly than Parkerized finishes
Expert review
Key attributes
| upc | 840442503819 |
| manufacturer | CMMG |
| manufacturer part number | 94AD90F-TNG |
| product type | AR |
| sights | Optics Ready |
| safety | Ambidextrous |
| action | Semi-Auto |
| barrel length | 5" |
| caliber/gauge | 9mm |
| capacity | 30 |
| color | TUNGSTEN |
| model | Banshee |
Frequently asked questions
- Is it compatible with Glock magazines?
- No, the Banshee Mk4 uses proprietary CMMG 9mm magazines only. These are modified Colt-style magazines with a dedicated follower and spring configuration. You'll need to purchase additional magazines directly from CMMG or authorized dealers.
- Does it work with SilencerCo Octane 9?
- Yes, the 1/2x28 threaded barrel accepts most 9mm suppressors including the SilencerCo Octane 9. I recommend using a fixed barrel spacer and checking alignment with an alignment rod before first use. Suppressor-ready pistols typically show 2-3% velocity increase compared to unsuppressed firing.
- How long does shipping take to Montana?
- FFL shipments typically take 3-5 business days via FedEx Priority Overnight. All firearms ship signature-required to your chosen FFL holder. We process transfers within 24 hours of payment verification and FFL documentation receipt.
- Can I return it if it doesn't cycle properly?
- Firearms sales are final except for manufacturer defects. If you experience cycling issues, CMMG's warranty covers repairs for 5 years from purchase date. Most cycling problems resolve with different ammunition or proper lubrication—9mm AR platforms often prefer 124 grain NATO-spec ammunition.