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

Kahr Arms X9
Kahr Arms X9

Review: Kahr Arms X9

When Kahr introduced the 10-round X9, it was first a matter of “about time.” However, after examining the pistol, it’s apparent that the company found a way to catch up with its competitors in a hurry.

Frugal Tactical: Retay USA's RA1522 Line

Largely known for its line of imported shotguns, Retay USA is moving into the tactical rimfire field with its collection of .22 LR-chambered RA1522 guns.

The Armed Citizen® March 9, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Firearm Industry Rebound on the Horizon?

Several industry developments indicate the post-pandemic decline in gun sales may finally be coming to a halt. Here's what that means for consumers.

Preview: Adapteur & Silencieux Silencer Adapter

Cleverly designed and precisely made in France by Adaptateur & Silencieux, the Ruger Mark IV, III and II Silencer Adapter allows those classic models to accept suppressors.

Review: Yankee Hill Machine Victra-12 Shotgun Suppressor

Yankee Hill Machine has recently released its Victra-12 shotgun suppressor, which promises to quiet the report of a 12-gauge shotgun while adding less weight than ever before.

Interests



Get the best of American Rifleman delivered to your inbox.