Editor’s Choice: CMMG 5.7 mm Conversion Kit

by
posted on May 19, 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. **
cmmgkit.jpg

CMMG has tapped into a cartridge that has long been a niche round for a select few enthusiasts: the 5.7x28 mm FN. The cartridge underwent a recent resurgence with the launch of the CMMG Mk57 Banshee in 2019 and received a bigger boost with the 2020 launch of the Ruger-57.

Now CMMG proves that it wasn’t finished with the 5.7 mm by rolling out a conversion kit for today’s AR-15 rifle owners. The Mk57 Banshee fed from Five-SeveN magazines, requiring added investment for anyone not already sitting on a stock of them.

However, the Mk57 AR Conversion Kit provides an opportunity for owners of mil-spec AR-15 lower receivers to get in on the 5.7 mm fun. The conversion 
includes a STANAG-size magazine that provides a reliable feeding platform for the company’s 5.7x28 mm FN upper receiver.

Best of all, these proprietary magazines hold 40 rounds each, providing twice the capacity of FN Five-SeveN pistol magazines. For more information on these CMMG 5.7 Conversion Kits, visit
cmmginc.com.

Latest

The Armed Citizen Podcast Hamlin F
The Armed Citizen Podcast Hamlin F

NRA CEO/EVP Doug Hamlin Talks Politics, the NRA, and the Future of Our Freedom

In this interview with The Armed Citizen Podcast at the 155th NRA Annual Meetings & Exhibits in Houston, Texas, NRA Executive Vice President and CEO Doug Hamlin talks about what is going on with the NRA, the many battles for our freedom around this nation the NRA is involved in, and what’s to come.

Best of the Best: American Rifleman's 2026 Golden Bullseye Award Winners

From firearms to accessories to optics to ammo and suppressors, we’ve determined these to be the stand-out products from the last year, providing firearm enthusiasts with innovation, value, utility and performance.

Review: Diamondback 9 mm SDR

Folks might be a bit surprised that Diamondback would choose 9 mm as the second caliber for its SDR revolver, but a closer look reveals why 9 mm is a solid caliber option for the platform.

Port Authority Doubles Down on Constitution-Free Zone with High-Profile Arrest

There exists a zone within the New York City metropolitan area where law-abiding gun owners are not just imperiled but specifically targeted for exercising their rights. It is an outrage that has continued for far too long.

Wilson Combat Acquires Guncrafter Industries

Wilson Combat has acquired the Guncrafter Industries brand and assets, uniting two of America’s foremost custom firearm manufacturers.

Bill Bachenberg Unanimously Reelected NRA President; Doug Hamlin Unanimously Reelected as NRA Executive Vice President & CEO In Houston

Today, the Board of Directors of the National Rifle Association of America (NRA), unanimously reelected Bill Bachenberg of Pennsylvania as President of the NRA, and Doug Hamlin as NRA Executive Vice President & CEO.

Interests



Get the best of American Rifleman delivered to your inbox.