New: CMMG 5.7x28mm to .22 LR Conversion Kit

by
posted on August 25, 2020
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
new-project.png (2)

CMMG has expanded its lineup with the addition of the Mk57 .22 LR AR Conversion Kit. Now, you can transform a CMMG 5.7x28mm upper receiver group into a .22 LR by swapping the bolt-carrier group and pairing with an AR-15/Mk4 lower receiver. Add in a dedicated CMMG .22 LR magazine, and you are ready to shoot rimfire.

The Mk57 .22 LR Conversion Kit is designed to be used with all existing CMMG Mk57 5.7x28mm upper receiver groups and bolt/barrel combinations, when paired with any AR-15/Mk4 lower receiver. Plus, no tools are required for installation.

Each kit includes the new .22 LR bolt-carrier group, and the choice of one or three 25-round magazines. In addition, CMMG has Mk57 5.7x28mm complete uppers available, in 5-, 8- and 16-inch barrel lengths.

MSRP ranges from $199.95 to $229.95, depending on the how many magazines you choose to purchase. Something to note, this kit is not compatible with Mk57 lower receiver groups or 5.56mm/.223 Rem. uppers. Learn more at cmmginc.com.


See more: Review: CMMG Resolute Mk4 PCC 9mm

Latest

Desi E Hof Nov2025 1
Desi E Hof Nov2025 1

Desirae Edmunds Takes Her Place in the NSCA Hall of Fame

Desirae Edmunds earns NSCA Hall of Fame induction, capping a sporting clays career defined by dominance and a decades-long rise from Alaska prodigy to global champion.

New: Mantis TitanX Laser Trainer

The new TitanX is an inert laser trainer pairing realistic controls with the MantisX analytics ecosystem for data-heavy dry-fire practice.

Collegiate Rifle: Nebraska Takes Over No. 1 Spot in CRCA Rankings; TCU, Navy Surge into Top Three

Nebraska claims the top CRCA rifle ranking, TCU surges to No. 2 with a big win and Navy jumps to No. 3.

Marksmanship Milestones: 1985 National Matches

The 1985 National Matches featured record scores, historic wins and major facility upgrades at Camp Perry.

Inside the 2025 NRA World Shooting Championship

Nils Jonasson claims top title at multi-discipline 2025 NRA World Shooting Championship, held at Camp Atterbury in October.

White Flyer, Winchester Boost South Dakota’s New Shooting Sports Complex with Massive Target Donation

Winchester Ammunition and White Flyer Targets fuel the debut of South Dakota’s new shooting sports complex with a major donation and focus on community growth.

Interests



Get the best of Shooting Sports USA delivered to your inbox.