The CMMG Banshee Mk4 5.7x28mm is a compact, AR-15-based pistol built for shooters who want effective personal defense in a package that goes places a full-size rifle can't. Chambered in the increasingly popular 5.7x28mm cartridge, this 5-inch-barreled platform delivers manageable recoil in a surprisingly potent defensive round—all while maintaining the ergonomics and modularity you expect from the modern AR platform. At just 20.9 inches overall and weighing 4.6 lbs, the Banshee Mk4 fits naturally in vehicle storage, home defense setups, or any scenario where compact firepower matters. Built on CMMG's proven Mk4 architecture using a standard AR15 lower receiver, it's as customizable as it is practical.

What sets the Banshee apart is its radial delayed blowback operating system, specifically engineered for the 5.7x28mm cartridge's ballistics. That design, combined with CMMG's ZEROED linear compensator, keeps the gun running smooth and flat while managing the recoil impulse. The billet upper receiver, forged 7075 T6 aluminum lower, and Cerakote finish speak to durability you can trust; the CMMG EML4 M-LOK handguard gives you plenty of real estate to mount lights, lasers, or other defensive accessories. The gun ships with a 32-round magazine and CMMG's RipBrace—a support you can rely on for consistent presentation and control.

If you've been curious about 5.7x28mm but weren't ready to abandon the AR ecosystem, the Banshee Mk4 is the bridge. It feeds from dedicated CMMG 5.7x28mm AR conversion magazines (not standard 5.56mm), so you're not compromising magazine reliability. The ambidextrous charging handle, drop-in trigger, and configurable safety selector make it equally at home in trained hands or as a learning platform for serious shooters. This is purpose-built personal defense hardware wearing the modularity of an AR—compact, capable, and distinctly CMMG.

The CMMG Banshee Mk4 5.7x28mm is a compact, AR-15-based pistol built for shooters who want effective personal defense in a package that goes places a full-size rifle can't. Chambered in the increasingly popular 5.7x28mm cartridge, this 5-inch-barreled platform delivers manageable recoil in a surprisingly potent defensive round—all while maintaining the ergonomics and modularity you expect from the modern AR platform. At just 20.9 inches overall and weighing 4.6 lbs, the Banshee Mk4 fits naturally in vehicle storage, home defense setups, or any scenario where compact firepower matters. Built on CMMG's proven Mk4 architecture using a standard AR15 lower receiver, it's as customizable as it is practical.

What sets the Banshee apart is its radial delayed blowback operating system, specifically engineered for the 5.7x28mm cartridge's ballistics. That design, combined with CMMG's ZEROED linear compensator, keeps the gun running smooth and flat while managing the recoil impulse. The billet upper receiver, forged 7075 T6 aluminum lower, and Cerakote finish speak to durability you can trust; the CMMG EML4 M-LOK handguard gives you plenty of real estate to mount lights, lasers, or other defensive accessories. The gun ships with a 32-round magazine and CMMG's RipBrace—a support you can rely on for consistent presentation and control.

If you've been curious about 5.7x28mm but weren't ready to abandon the AR ecosystem, the Banshee Mk4 is the bridge. It feeds from dedicated CMMG 5.7x28mm AR conversion magazines (not standard 5.56mm), so you're not compromising magazine reliability. The ambidextrous charging handle, drop-in trigger, and configurable safety selector make it equally at home in trained hands or as a learning platform for serious shooters. This is purpose-built personal defense hardware wearing the modularity of an AR—compact, capable, and distinctly CMMG.