CMMG 57A9A0FAB BANSHEE MK57 5.7x28mm Carbine

The CMMG Banshee MK57 in 5.7x28 is a radial delayed blowback platform purpose-built around the FN Five-seveN cartridge. This compact 5-tube configuration delivers the ballistic advantages of 5.7x28—reduced recoil, lower noise signature, and FN magazine compatibility—in a package optimized for close-quarters operations, specialized team work, and shooters seeking an alternative to traditional pistol caliber carbines.

The radial delayed blowback operating system provides reliable function while managing recoil impulse inherent to the 5.7x28 cartridge. The receiver accepts standard FN Five-seveN pattern magazines, eliminating the need for custom ammo logistics on teams already running the pistol. The platform ships with a complete kit of zeroed components—drop-in trigger, ambi safety (60/90 degree), linear compensator tuned for 9mm ballistics, AR-15 ambi charging handle, bolt catch, and polymer dust cover—enabling immediate operational readiness. Full-length M-LOK slots run the length of both sides and bottom of the handguard, plus M-LOK mounting between top picatinny sections, providing flexible accessory integration for optics, lights, and rail systems without rail clutter.

This configuration is favored by operators seeking a non-lethal capable platform, specialized threat response teams, and precision shooters working in noise-sensitive environments. The 5.7x28 cartridge's inherent accuracy and flat trajectory make the Banshee MK57 effective at intermediate ranges while the compact footprint suits vehicle-based operations, buildings clear, and travel-restricted scenarios. The oversized mag release ensures positive indexing and rapid magazine changes under stress, critical for dynamic action sequences.

CMMG's radial delayed blowback design establishes the Banshee platform as a purpose-built alternative to direct impingement systems, favored by operators who prioritize ergonomics and modularity alongside established 5.7x28 supply chains. The platform's straightforward maintenance, FN magazine ecosystem, and extensive rail real estate position it within the growing category of specialized duty carbines designed for defined operational niches rather than universal duty application.