CMMG MK57 5.7x28mm Pistol

This very good, used CMMG MK57 is a compact, modern AR-style pistol chambered in 5.7x28mm, designed for shooters who want lightweight recoil, high velocity performance, and increased magazine capacity in a compact platform. This platform offers smoother operation and reduced recoil impulse compared to traditional blowback designs—making it fast, controllable, and enjoyable on the range.

This model features a sleek M-LOK handguard for easy accessory mounting, a full-length top rail for optics, and a compact barrel that keeps the overall footprint tight without sacrificing performance. The inclusion of a stabilizing brace enhances control and versatility, making it ideal for range use, home defense setups, or anyone looking for a lightweight, maneuverable platform.

Compatible with FN-pattern 5.7 magazines, the MK57 stands out as a unique alternative to standard AR calibers. Whether you’re building a modern defensive setup or just want something different that performs exceptionally well, this platform delivers reliability, innovation, and fun in one package.