First Look: CMMG 5.7x28 mm AR Conversion

by
posted on January 15, 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. **
cmmg-inc-57x28mm-ar-conversion-magazine-upper-receiver-f.jpg
In 2020, the 5.7x28 mm cartridge is coming back in a big way, and CMMG joined multiple companies in offering a new option for fans of this high-velocity cartridge. Following up on the success of the company's Banshee chambered in 5.7x28 mm, CMMG now offers an AR-15 conversion package that allows shooters to mate their mil-spec AR-15 lower receiver with the company's 5.7x28 mm Radial Delayed Blowback upper-receiver group.

The key to this conversion lies in CMMG's 5.7 AR Conversion Magazine, which is designed to fit into standard AR-15 magazine wells while providing a reliable feed mechanism that's compatible with the company's 5.7x28 mm upper receiver. To convert any standard AR-15 to a 5.7 mm firearm, simply remove the existing upper-receiver group and replace it with a compatible, 5.7x28 mm upper receiver from CMMG. Once the upper receiver is installed, users can simply insert a CMMG 5.7 AR Conversion Magazine into the mil-spec magazine well.

In addition to allowing AR owners to experiment with the 5.7x28 mm cartridge without having to purchase an entirely new firearm, this CMMG conversion system maintains the controls and configuration of any existing AR-15 lower. If users have an enhanced trigger installed in their gun or optimized controls, they can continue using those components without having to invest in or learn an entirely new firearm. CMMG recommends the use of a standard carbine buffer and action spring to run the 5.7x28 mm conversion reliably, and the magazine provides last-round bolt hold-open capability.

A complete lineup of CMMG Banshee and Resolute upper receivers are compatible with the 5.7 AR Conversion Magazine. CMMG's Mk57 upper receivers can be had in 5", 8" and 16" barrel lengths, and the uppers ship complete with bolt-carrier group and charging handle. A single CMMG 5.7 AR Conversion Magazine holds 40 rounds of 5.7x28 mm, and the suggested retail price on the mag is $39.95. Suggested retail pricing on the Mk57 upper receiver complete with three 40-round magazines starts at $799.95. For more information on these conversion kits, visit cmmginc.com.


Latest

Customizing X Card Shotgun 1
Customizing X Card Shotgun 1

Building an X-Card Gun for Turkey Shoots

Unofficially known as a “turkey shoot,” X-Card competition challenges shotgunners to place shot pellets as closely as possible to the center of a target. And some makers have perfected a way to fine-tune shotguns for this purpose.

Spanish National Police Adopt Springfield Armory Echelon 4.0FC

The Spanish National Police (Policia Nacional) has officially adopted the Springfield Armory Echelon 4.0FC 9mm pistol as the issue pistol for its uniformed officers.

NRA Launches New NRA.org Platform and Official App to Modernize and Enhance the Member Experience

The National Rifle Association today launched its new NRA.org website and continued enhancements to the official NRA App, marking a major step and significant investment to modernize the organization and better serve members.

Political Report | Federal Firearms Rights Restoration is Officially Back

Criminal-justice reform has been distorted to mean counterproductive policies like eliminating cash bail or politicized district attorneys exhibiting a determined indifference to violence, but there is a place for sensible reforms that allow genuinely rehabilitated offenders to reintegrate into the community of law-abiding citizens.

Stable Fun: The Taurus Brace-Ready TX22

Taurus USA first adopted the ideal of a brace-ready format for a traditional handgun in its GX4 Strike Bravo, and now, the company is extending that concept to its TX22 rimfire handgun.

I Have This Old Gun: The Whitney Navy Revolver

One of the lesser-known revolvers from the Civil War era, the Whitney Navy revolver had several notable features and even inspired a copycat in the Confederacy.

Interests



Get the best of American Rifleman delivered to your inbox.