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

Ihtog Walther P38 1
Ihtog Walther P38 1

I Have This Old Gun: Walther P38

On the eve of World War II, the German military sought a new sidearm that was easier to manufacture than the P08 Luger. Its answer was the P38.

C&H Precision STRYKR: A Red-Dot Sight for PDWs

The C&H Precision STRYKR is a hard-use, enclosed-emitter optic designed for PDWs and compact carbines.

Rifleman Interview: Smith & Wesson M&P15-22 OD Green Topographic Rifle

At “Plinkapalooza” in May we had a chance to try out the latest Smith & Wesson M&P15-22 rifle.

Patriots Landing Announces "A Nation Remembers" Veterans Weekend

Patriots Landing, a faith-based veterans workshop based in Kentucky, announced it would hold "A Nation Remembers" veterans weekend in Grant County, Ky., from Sept. 16-20.

Past NRA President Allan Cors, 1936-2026: Liberty Takes A Loss

One of liberty’s champions, past NRA President Allan D. Cors died on August 10, 2026.

Moving to the Micro Red-Dot: An Old Dog Learns Some New Tricks

After shooting open-sighted handguns for more than 40 years, the author's aging eyes finally caught up to him, and his concealed-carry pistol now sports a red-dot optic.

Interests



Get the best of American Rifleman delivered to your inbox.