CMMG BANSHEE MK4 | 5.7x28mm | 8

The CMMG BANSHEE MK4 is built on the Mk4 AR15 platform and is chambered for the 5.7x28mm cartridge. It features an 8 barrel and uses a standard AR15 lower receiver with CMMG’s 5.7x28mm AR conversion magazines. The action is a radial delayed blowback design and the pistol ships with a CMMG 32rd magazine. For an affordable optic that pairs well for fast target acquisition and durability, consider a Holosun 507C-class red dot (priced under $1,000).

Suitable applications include range training and pistol-caliber competition where low recoil and high magazine capacity are desirable.

Product Specifications

• The platform is Mk4.
• The caliber is 5.7x28mm.
• The operating system is Radial Delayed Blowback.
• The barrel length is 8.
• The barrel twist is 1:9.
• The barrel contour is MT.
• The barrel material is 4140CM SBN.
• The muzzle device is CMMG ZEROED Linear Compensator.
• The muzzle thread is 1/2 x 28.
• The upper receiver is Billet 6061 T6 Aluminum.
• The lower receiver is Mk4 Forged 7075 T6 Aluminum.
• The hand guard is CMMG EML7 M-LOK.
• The finish is Cerakote.
• The magazine is CMMG 32rd.
• The weight is 4.6 lbs.
• The UPC is 810144723716.

This BANSHEE MK4 balances compact handling with the unique ballistics of 5.7x28mm. The Mk4 AR15-based design and full-length M-LOK options on the handguard keep accessory choices broad while the included CMMG 32-round magazine maintains extended capacity for range sessions and competitive stages. The combination of a radial delayed blowback system and a ZEROED drop-in trigger supports consistent, controllable follow-up shots without excessive recoil impulse.