The CMMG Banshee Mk4 (CMMG part no. 54AE10FAB) chambers the increasingly popular 5.7x28mm cartridge in a familiar AR15 footprint. This cartridge delivers rifle-like ballistics with noticeably less recoil than most pistol-caliber carbines, and CMMG built this Banshee on its Mk4 platform, which runs a standard AR15 lower rather than a proprietary receiver. That means the modularity shooters already know from the AR ecosystem carries straight over. With an 8-inch barrel and a deep 32+1 capacity, this is a serious, easy-shooting personal-defense pistol finished in CMMG‘s armor black.

Key Specifications

• Chambered in 5.7x28mm, delivering rifle-caliber-like ballistics with less recoil than typical pistol-caliber carbines.
• Holds 32+1 rounds per magazine for a substantial reserve of ready ammunition.
• Runs an 8-inch barrel that keeps the package compact while still extracting solid velocity from the cartridge.
• Built on CMMG’s Mk4 platform, which uses a standard AR15 lower receiver instead of a proprietary design.
• Cycles off a radial delayed blowback operating system tuned specifically for the 5.7x28mm cartridge.
• Runs a CMMG Zeroed linear compensator muzzle device to help tame muzzle rise.
• Wears a CMMG EML M-LOK handguard for a full-length accessory mounting surface.
• Equipped with CMMG’s Zeroed 60/90-degree safety for a shorter, faster selector throw.
• Cycles in reliable semi-auto for controlled, repeatable follow-up shots.
• Weighs approximately 5 pounds unloaded, keeping the package easy to carry and maneuver.
• Finished in armor black for a tough, low-glare exterior.

Frequently Asked Questions

Does this pistol use a standard AR15 lower? Yes, the Mk4 platform is built on a standard AR15 lower receiver, so it’s compatible with the broader AR parts ecosystem.

How many rounds does the magazine hold? Each magazine holds 32+1 rounds of 5.7x28mm.

What kind of safety selector does it have? It uses CMMG’s Zeroed 60/90-degree safety for a quick, positive throw.

Buy the CMMG Banshee Mk4 Pistol, 5.7x28mm, 8-Inch, Armor Black

This Mk4 Banshee combines a hot-selling defensive caliber with the modularity of a platform shooters already know inside and out. The 32+1 capacity gives you plenty of rounds on tap without adding bulk. Order it from our AR pistols lineup at our Lubbock, Texas gun shop for fast, insured shipping to your FFL.