CMMG BANSHEE MK4 | 5.7x28mm | 5″ Barrel | 32rd

The CMMG Banshee MK4 in 5.7x28mm is an ultra-compact AR-platform pistol designed around a 5″ barrel for tight handling in confined carry or transport. Built on CMMG’s Mk4 architecture and using purpose-made 5.7x28mm conversion magazines, it offers reduced recoil compared with typical rifle calibers at short ranges. For sighting, a rugged low-power variable or 1x optic such as a Trijicon MRO pairs well and stays comfortably under $1,000.

Common applications include precision-oriented pistol-caliber competition and range training where compact size and controllable recoil are priorities.

Product Specifications

• Caliber is 5.7 x 28 mm.
• Capacity is 32 rounds.
• The barrel measures 5 inches for compact handling.
• The barrel twist rate is 1:9.
• The operating system is Radial Delayed Blowback.
• The barrel material is listed as 4140CM with SBN.
• The muzzle device is a CMMG ZEROED Linear Comp and the muzzle is threaded 1/2 x 28.
• The upper receiver is machined from billet 6061 T6 aluminum.
• The lower receiver is a Mk4 forged 7075 T6 aluminum lower.
• The handguard is a CMMG EML4 M-LOK style.
• The finish is Cerakote Standard.
• The stock/brace is a CMMG RipBrace pistol brace.
• The trigger is a ZEROED drop-in single-stage trigger.
• The magazine included is a CMMG 32-round magazine.
• The UPC is 810148624163.

Compact, mechanically straightforward, and built on a standard AR15 interface, the Banshee MK4 offers a practical way to run the 5.7x28mm cartridge from an AR-style pistol platform. Its short barrel and lightweight receiver construction make it easy to maneuver on the range while still accepting standard Mk4 lowers and the CMMG conversion magazines specific to 5.7x28mm. If you value a compact package for precision pistol-caliber work and competition, this model is purpose-built to deliver consistent handling and control.

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