CMMG is expanding its line of conversion kits to include a new adapter for Mk57 upper receiver groups called the Mk57 .22 LR AR Conversion Kit. This will let people with these uppers shoot .22 Long Rifle ammunition in addition to 5.7x28mm ammo.
CMMG offers a range of conversion uppers chambered for 5.7x28mm that convert standard AR-15 lowers to shoot the popular personal defense weapon cartridge. With these kits the same uppers can fire inexpensive rimfire ammo, too.
This way shooters can practice and plink using the same uppers, optics and accessories but at a lower cost in the long run. The kit uses conversion magazines that work with MIL-SPEC and compatible lower receivers, like CMMG’s 5.7mm conversion magazines.
“Converting any CMMG Mk57 upper to shoot .22LR is a great way to reduce cost with each pull of the trigger, all while reducing recoil and muzzle flash,” said CMMG in the announcement. “Anyone who is interested in 5.7x28mm. but concerned about ammo prices, can take advantage of cost-effective rimfire training. It’s the ultimate tool for young or first-time shooters.”
The Mk57 .22 LR AR Conversion Kit will work with all of CMMG’s 100, 200 and 300 series 5.7mm upper receivers. These uppers are offered in a handful of different configurations with 5-, 8- and 16-inch barrels.
The kit includes a bolt assembly and one or three conversion mags. Standard magazine capacity is 25 rounds for .22 LR and reduced capacity compliant magazines are also available. The kit with one mag carries a $199 suggested retail price while the kit with three mags runs $229.
Additional magazines run $24 so the three mag kit offers a solid value for only $30 more. Of course, to use them you’ll also need a Mk57 upper.
Pricing for CMMG Mk57 uppers starts at $724, which is not inexpensive but in-line with other similar AR-15 upper receivers. CMMG also offers 5.7x28mm bolt assembly and barrel kits for builders that start at $399, giving shooters a lot of options in order to get into 5.7mm AR-pattern rifles and pistols.
For more information about these kits, other conversion parts and accessories, and complete CMMG firearms, head over to the company website.