Gaining more acceptance as the go to personal defense caliber for many shooters in recent years 5.7x28mm has proven itself to be well suited for the job. With incredibly flat shooting performance and low recoil 5.7x28 excels at closer ranges while still providing ideal penetration. Equipped with a 5” barrel this is the most compact 5.7x28mm upper group CMMG® offers. CMMG 5.7x28mm uppers are designed to work with CMMG Mk57™ lowers or standard AR15/Mk4 lowers (when used with 5.7 AR Conversion Mags). All CMMG® Upper Groups come complete with bolt carrier group and ZEROED™ accessories including:
ZEROED AR15 Polymer Dust Cover
ZEROED AR15 Ambi Charging Handle
ZEROED Linear Compensator 5.56mm
Radial Delayed Blowback™ Operating System
Originally developed for the .45 ACP MkG platform CMMG has adapted the Radial Delayed Blowback system across their pistol caliber lineup to create pistols and rifles with a softer recoil impulse and reduced bolt weight compared to traditional straight blowback systems.
