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

Smith Wesson Academy Artv 1
Smith Wesson Academy Artv 1

The Smith & Wesson Academy Reopens

One of the latest expansions at S&W's new Maryville facility is the addition of an entirely new training ground, the new home of the legendary Smith & Wesson Academy.

New for 2026: EAA Balikli BLK Bolt-Action Rifles

This year, EAA Corp. expanded its catalog with a new hunting rifle, the Balikli BLK bolt-action, which has high-end features for its price, as well as compatibility with broad aftermarket.

HOUSTON 2026 | The 155th NRA Annual Meetings & Exhibits

Exuberance was the defining spirit of the 2026 NRA Annual Meetings. More than 73,000 attendees packed the George R. Brown Convention Center in Houston to celebrate 250 years of America, concurrent with 155 years of their NRA.

Shotshell Basics: Understanding Payloads, Pressures & Performance

A shotgun can be supremely versatile, depending on how it’s loaded. Understanding how shotshells work is difficult, but crucial.

Rock River Arms Celebrates 30 Years in Business

While the company's beginnings go back to 1994, the Rock River Arms story officially started in 1996, meaning that it is celebrating 30 years in business in 2026.

Review: Daniel Defense H9

Is the third time the charm? Daniel Defense has introduced a third version of the Hudson H9 pistol. Smaller, lighter and less radical, it could be “the one.”

Interests



Get the best of American Rifleman delivered to your inbox.