CMMG145480054
Cmmg Banshee 54Ae10Fab Mk4 5.7X28 8 Brc Arblk$1,512.64
Availability: In Stock
Current Stock: Out of stock
The CMMG Banshee Mk57 in 5.7x28mm is a modern AR-pattern pistol built around a platform purpose-designed for this emerging defensive cartridge. With an 8-inch barrel, the Banshee harnesses the full potential of 5.7x28 ballistics in a compact, maneuverable package ideal for close-quarters personal defense. If you're drawn to the flat-shooting, low-recoil characteristics of 5.7x28 but want AR ergonomics and controls, the Mk57 platform delivers both—and it does it without sacrificing the familiar features that make modern rifles so reliable.
The radial delayed blowback operating system keeps the Banshee running clean and controllable. The billet aluminum upper and forged lower receivers are built tough, while the CMMG EML7 M-LOK handguard gives you mounting flexibility for lights, lasers, or other modern accessories. You get last-round bolt hold-open, an ambidextrous charging handle, and a 60/90-degree safety selector—conventional AR functionality that shouldn't have to be sacrificed just because you're running pistol magazines. The included 20-round Promag magazine keeps capacity respectable while maintaining Five-seveN-pattern magazine compatibility, so you've got options in the field.
The CMMG ZEROED Linear Compensator mitigates muzzle rise without unnecessary blast signature, and the RipBrace stabilizer keeps the platform solid in your hands. At 5.2 pounds and 23.7 inches overall, the Banshee balks at neither carry nor control. This is a purpose-built 5.7x28 platform for shooters who want AR reliability and modularity in a caliber that's gaining traction with serious defensive shooters.
| Caliber | 5.7x28mm |
| Platform | CMMG Mk57 |
| Operating System | Radial Delayed Blowback |
| Barrel Length | 8 inches |
| Barrel Material | 4140CM Steel |
| Barrel Twist Rate | 1:9 |
| Barrel Contour | MT |
| Muzzle Device | CMMG ZEROED Linear Compensator |
| Muzzle Thread | 1/2 x 28 |
| Upper Receiver | Billet 6061-T6 Aluminum |
| Lower Receiver | Mk57 Forged 7075-T6 Aluminum |
| Handguard | CMMG EML7 M-LOK |
| Charging Handle | CMMG ZEROED Ambidextrous |
| Pistol Grip | CMMG ZEROED |
| Trigger Type | ZEROED Drop-In Single Stage |
| Trigger Guard | Integrated |
| Safety Selector | CMMG ZEROED 60/90 Degree |
| Receiver Extension | CMMG 6-Position Fastback |
| Stock/Brace | CMMG RipBrace |
| Buffer Type | Carbine |
| Magazine Included | 20-round Promag |
| Finish | Cerakote Standard |
| Weight | 5.2 lbs |
| Overall Length | 23.7 inches |
The Banshee is built around the Mk57 platform and accepts FN Five-seveN–pattern magazines. The pistol ships with a 20-round Promag magazine, but you can use other compatible 5.7x28 magazines designed for the Five-seveN platform.
The Banshee Mk57 is purpose-designed as a personal defense weapon in 5.7x28mm. The 8-inch barrel is tuned to maximize the ballistic potential of this cartridge at close-range defensive distances, and the compact, light design makes it maneuverable for that role.
Yes, the Banshee comes equipped with the CMMG RipBrace, which provides a stable platform for controlled operation.
The Banshee Mk57 weighs 5.2 pounds and measures 23.7 inches overall in length, making it a compact, portable platform despite its AR-pattern construction.
SKU: 145480067 • Weight: 6.93oz
Availability: In Stock
Current Stock: Out of stock
The CMMG Banshee Mk57 in 5.7x28mm is a modern AR-pattern pistol built around a platform purpose-designed for this emerging defensive cartridge. With an 8-inch barrel, the Banshee harnesses the full potential of 5.7x28 ballistics in a compact, maneuverable package ideal for close-quarters personal defense. If you're drawn to the flat-shooting, low-recoil characteristics of 5.7x28 but want AR ergonomics and controls, the Mk57 platform delivers both—and it does it without sacrificing the familiar features that make modern rifles so reliable.
The radial delayed blowback operating system keeps the Banshee running clean and controllable. The billet aluminum upper and forged lower receivers are built tough, while the CMMG EML7 M-LOK handguard gives you mounting flexibility for lights, lasers, or other modern accessories. You get last-round bolt hold-open, an ambidextrous charging handle, and a 60/90-degree safety selector—conventional AR functionality that shouldn't have to be sacrificed just because you're running pistol magazines. The included 20-round Promag magazine keeps capacity respectable while maintaining Five-seveN-pattern magazine compatibility, so you've got options in the field.
The CMMG ZEROED Linear Compensator mitigates muzzle rise without unnecessary blast signature, and the RipBrace stabilizer keeps the platform solid in your hands. At 5.2 pounds and 23.7 inches overall, the Banshee balks at neither carry nor control. This is a purpose-built 5.7x28 platform for shooters who want AR reliability and modularity in a caliber that's gaining traction with serious defensive shooters.
| Caliber | 5.7x28mm |
| Platform | CMMG Mk57 |
| Operating System | Radial Delayed Blowback |
| Barrel Length | 8 inches |
| Barrel Material | 4140CM Steel |
| Barrel Twist Rate | 1:9 |
| Barrel Contour | MT |
| Muzzle Device | CMMG ZEROED Linear Compensator |
| Muzzle Thread | 1/2 x 28 |
| Upper Receiver | Billet 6061-T6 Aluminum |
| Lower Receiver | Mk57 Forged 7075-T6 Aluminum |
| Handguard | CMMG EML7 M-LOK |
| Charging Handle | CMMG ZEROED Ambidextrous |
| Pistol Grip | CMMG ZEROED |
| Trigger Type | ZEROED Drop-In Single Stage |
| Trigger Guard | Integrated |
| Safety Selector | CMMG ZEROED 60/90 Degree |
| Receiver Extension | CMMG 6-Position Fastback |
| Stock/Brace | CMMG RipBrace |
| Buffer Type | Carbine |
| Magazine Included | 20-round Promag |
| Finish | Cerakote Standard |
| Weight | 5.2 lbs |
| Overall Length | 23.7 inches |
The Banshee is built around the Mk57 platform and accepts FN Five-seveN–pattern magazines. The pistol ships with a 20-round Promag magazine, but you can use other compatible 5.7x28 magazines designed for the Five-seveN platform.
The Banshee Mk57 is purpose-designed as a personal defense weapon in 5.7x28mm. The 8-inch barrel is tuned to maximize the ballistic potential of this cartridge at close-range defensive distances, and the compact, light design makes it maneuverable for that role.
Yes, the Banshee comes equipped with the CMMG RipBrace, which provides a stable platform for controlled operation.
The Banshee Mk57 weighs 5.2 pounds and measures 23.7 inches overall in length, making it a compact, portable platform despite its AR-pattern construction.
SKU: 145480067 • Weight: 6.93oz