Description

The CMMG Banshee Mk17 fills the role of a compact personal defense weapon (PDW) by combining the AR pistol platform with the Mk17 lower receiver, which accepts Sig Sauer P320, M17, and M18 pattern magazines. This allows shooters who already carry or train with P320-family pistols to use the same magazines, magazine pouches, and accessory ecosystem across both platforms. The standard-capacity Sig Sauer P320 21-round magazine ships with the firearm.

The operating system is CMMG's Fixed Ejector Radial Delayed Blowback — an evolution of their original Radial Delayed Blowback design. By using a small number of locking lugs on the bolt that briefly engage the barrel extension before unlocking, the system delays rearward bolt travel compared to a traditional straight blowback design, producing a softer recoil impulse and allowing for a lighter bolt carrier. The fixed ejector is an advancement over the earlier pivoting ejector design on the same platform. The 5" barrel is chrome-moly steel (4140CM) with a Salt Bath Nitride (SBN) finish and a 1:10" twist rate, threaded 1/2×28 and fitted with a ZEROED Radial Blowback Brake. The upper receiver is billet 6061-T6 aluminum; the lower is Mk4 forged 7075-T6 aluminum. The EML4 M-LOK handguard provides M-LOK attachment slots at the 3, 6, and 9 o'clock positions and a full-length Picatinny top rail, along with an integrated handstop. The CMMG 6-Position Fastback receiver extension hosts the CMMG RipBrace stabilizing brace. All CMMG ZEROED parts — including the drop-in trigger, ambi safety, ambi charging handle, bolt catch, pistol grip, and polymer dust cover — are included as standard equipment. The firearm is manufactured in the USA and backed by CMMG's Lifetime Quality Guarantee against material and workmanship defects.

Key Features

• Firearm Type: Pistol (AR-pattern, pistol caliber)
• Action: Semi-automatic, Fixed Ejector Radial Delayed Blowback
• Caliber: 9mm Luger
• Capacity: 21 rounds (Sig Sauer P320 pattern magazine)
• Barrel Length: 5"
• Overall Length: 20.8"
• Weight (Unloaded): 4.5 lbs
• Upper Receiver Material: Billet 6061-T6 Aluminum
• Lower Receiver Material: Mk4 Forged 7075-T6 Aluminum
• Barrel Material: 4140 Chrome-Moly Steel, Salt Bath Nitride (SBN) finish
• Twist Rate: 1:10"
• Barrel Contour: Medium Taper (MT)
• Muzzle Device: ZEROED Radial Blowback Brake
• Threaded Barrel: Yes – 1/2×28
• Trigger Type: ZEROED Drop-In Single Stage
• Safety Features: ZEROED 60°/90° Ambidextrous Safety Selector; Integrated Trigger Guard
• Optics Mounting: Full-length Picatinny top rail (EML4 handguard)
• Handguard: CMMG EML4 M-LOK (M-LOK slots at 3, 6, and 9 o'clock; integrated handstop)
• Brace: CMMG RipBrace
• Receiver Extension: CMMG 6-Position Fastback
• Buffer Type: Carbine
• Magazine Compatibility: Sig Sauer P320 / M17 / M18 pattern magazines
• Finish: Tungsten Cerakote
• Platform: Mk17
• Country of Manufacture: USA

Use Case

• Fixed Ejector Radial Delayed Blowback operating system reduces recoil impulse compared to traditional straight blowback designs, enabling faster follow-up shots from a 5" barreled platform
• Mk17 lower accepts Sig Sauer P320, M17, and M18 pattern magazines, allowing direct magazine interchangeability with P320-family sidearms for unified logistics
• 1/2×28 threaded barrel accepts 9mm Luger-compatible suppressors and muzzle devices without modification
• Full-length Picatinny top rail and M-LOK slots at 3, 6, and 9 o'clock on the EML4 handguard allow mounting of optics, lights, lasers, and other accessories
• 20.8" overall length and RipBrace stabilizing brace provide a compact, maneuverable footprint suited for vehicle operations, home defense, and close-quarters use
• ZEROED ambidextrous safety selector and ambi charging handle support left- and right-handed operation without modification

Compliance & Legal Notes

• FFL Transfer Required: This firearm must ship to a licensed Federal Firearms Licensee (FFL) and will be transferred to the buyer in accordance with federal, state, and local law.
• Shipping Restrictions Apply: Some jurisdictions restrict or prohibit certain firearms or features. Orders may be modified or canceled if delivery is not legally permitted.
• Buyer Responsibility: The buyer is responsible for ensuring this firearm is legal to purchase, possess, and transfer in their jurisdiction.

Box / Package Contains

• One factory-new CMMG Banshee Mk17 pistol in Tungsten Cerakote
• One Sig Sauer P320 pattern 21-round magazine
• CMMG RipBrace stabilizing brace (installed)
• ZEROED Radial Blowback Brake (installed)
• CMMG EML4 M-LOK handguard (installed)
• ZEROED Drop-In Single Stage trigger (installed)
• ZEROED 60°/90° Ambidextrous Safety Selector (installed)
• ZEROED Ambidextrous AR15 Charging Handle (installed)
• ZEROED AR15 Bolt Catch (installed)
• ZEROED AR15 Polymer Dust Cover (installed)
• ZEROED Pistol Grip (installed)
• Manufacturer lock
• Owner's manual
• Note: Orders shipping to jurisdictions with magazine capacity restrictions will substitute a 10-round magazine in place of the standard 21-round magazine in compliance with applicable law.