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

AC Podcast Screenshot With Greenlee 9.16.26
AC Podcast Screenshot With Greenlee 9.16.26

The History of Repeating Arms Gun-Control Groups Don’t Want the Courts to Know

This episode of NRA’s The Armed Citizen Podcast refutes one of the biggest false claims gun-control groups and the politicians they support repeat ad nauseam by asserting that the Founding Fathers could not have imagined the AR-15.

Rifleman Review: Springfield Armory Kuna

Initially designed by Croatian manufacturer HS Produkt to fulfill a military contract, the Kuna has since arrived on U.S. shores through Springfield Armory as a semi-automatic, large-format handgun chambered for the 9 mm Luger cartridge.

All-American AK: The Bear Creek Arsenal BC-47

North Carolina’s Bear Creek Arsenal makes AR-15s, 10/22s and handguns, but new for 2026, it is introducing its first AK-pattern firearm with the BC-47.

Review: TNW Firearms ASR 1911

Reliable pistol-caliber carbines, especially with quick-caliber-change capability, are fun, and the ASR 1911 from TNW Firearms is one of the most unique of the bunch.

GOEX Resumes Black Powder Production

Voyager Technologies announced on Sept. 8 that the GOEX plant in Camp Minden, La.—the sole black powder manufacturing facility located in the United States—has been modernized and is back in production.

NRA-ILA Names SIG SAUER Official Partner of the 2026 NRA Gun Bus Battleground Tour

New Hampshire-based firearms and weapons-systems maker joins NRA-ILA on the road.

Interests



Get the best of American Rifleman delivered to your inbox.