CMMG's Banshee MK4 is a 9mm AR-pattern pistol featuring a 5-inch barrel, fixed ejector system, and RipBrace. Built on a forged aluminum lower with billet upper, it includes an EML handguard with M-LOK slots and ships with a 30-round magazine.
The Banshee MK4 represents a thoughtful approach to 9mm pistol-caliber carbines. Built on CMMG's proven Mk4 platform, this compact firearm delivers the ergonomics and controls of an AR-pattern rifle in a more maneuverable package.
The Banshee MK4 employs a fixed ejector radial delayed blowback system, a design choice that provides reliable function without the complexity of a traditional gas tube. The 5-inch barrel is cold-hammer-forged from 4140 chromium-molybdenum steel with a 1:10 twist rate optimized for 9mm ammunition.
Receivers: The upper is machined from 6061-T6 billet aluminum, while the lower is forged from 7075-T6 aluminum. This combination provides durability and precision fit.
Handguard: The CMMG EML4 M-LOK handguard features full-length slots on both sides and the bottom, plus M-LOK sections between top Picatinny rail sections. This gives you flexibility for mounting optics, lights, and other accessories.
The Banshee MK4 uses CMMG's 9mm AR conversion magazines. If you already own standard AR-15 PMAGs, CMMG offers 9mm conversion adapters to repurpose them for this platform.
The Banshee MK4 is an excellent choice for shooters seeking a compact, reliable 9mm platform with familiar AR controls and modern ergonomics.