The CMMG Banshee Mk4 pistol in 5.7x28mm with an 8-inch barrel and black Cerakote finish (brand part no. 54AE40FAB) is built on CMMG’s Mk4 AR15 platform, using a standard AR15 lower receiver paired with CMMG’s 5.7x28mm AR conversion magazines so no proprietary lower is required. CMMG runs the pistol on a radial delayed-blowback operating system, giving 5.7x28mm’s rifle-like ballistics with less recoil than most pistol-caliber carbines. The billet 6061 T6 aluminum upper and forged 7075 T6 aluminum lower pair with a CMMG EML7 M-LOK handguard offering full-length M-LOK slots on both sides and the bottom, plus M-LOK between the top Picatinny rail sections for mounting accessories. A CMMG ZEROED linear compensator, ambidextrous charging handle, and drop-in trigger complete the build. Among AR-platform semi-auto handguns, this Banshee Mk4 configuration favors shooters who want a modular personal-defense pistol with rifle-caliber performance.

Key Specifications

• The chambering is 5.7x28mm, delivering rifle-like ballistics with reduced recoil.
• The barrel measures 8 inches, with a 1:9 twist rate.
• The operating system is radial delayed blowback, engineered for the caliber.
• The handguard is a CMMG EML7 M-LOK design with full-length slots.
• The magazine capacity is 32 rounds, using CMMG’s proprietary conversion magazine.
• The unloaded weight is 4.6 pounds, and overall length is 23.7 inches.
• The muzzle device is a CMMG ZEROED linear compensator on a 1/2×28 thread.

Frequently Asked Questions

Does this pistol use a proprietary lower receiver? No, it’s built on a standard AR15 lower receiver with CMMG’s 5.7x28mm conversion magazines.

What magazine capacity does this pistol use? A 32-round CMMG magazine ships with the pistol.

Buy the CMMG Banshee Mk4 Pistol, 5.7x28mm

Rifle-caliber performance in a modular AR-pattern personal-defense pistol is exactly what this Banshee Mk4 delivers. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.