Preview: CMMG Barrel and BCG Kit In .45 ACP

by
posted on January 5, 2022
** 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 Barrel

Established in 2002, CMMG continues its innovative engineering by providing DIY kits to at-home builders of AR-15-type guns. Whether building from scratch, or converting previously built guns into custom works, hobbyists and professionals alike benefit from the unique engineering CMMG Inc. has to offer. The MkG 8" Barrel and BCG Kit presents the DIY gun-builder with a pistol-caliber option for AR-15-type systems that utilizes a highly sought-after, big-bore chambering: .45 ACP.

With a patent pending design, the Barrel and BCG Kit converts the conventional gas-operated AR-15 action. The adaptation is relatively simple and requires fewer parts than Stoner's original action design. The combination that CMMG created, increases reliability of semi-automatic pistol cartridges and combines to help reduce overall weight and fouling, making for a lightweight, clean- and cool-running action.

CMMG’s Radial Delayed Blowback (RDB), though patent pending, completely alters system functionality. Rather than routing burnt propellant into the action, CMMG’s RDB system harnesses energy from the fired cartridge case to initiate a delay and blowback sequence that, in design, maintains semi-automatic function with improved mechanics. Previous American Rifleman testing has confirmed the RDB system’s ability to provide repeatable performance.

The MkG 8" Barrel and BCG Kit chambered for .45 ACP gives gun builders a 4140 chrome-moly-steel barrel with a 1:16" twist rate and a .578x28 TPI threaded muzzle. In addition to the barrel, the kit’s bolt carrier group is configured to employ the company’s Radial Delayed Blowback operating system. This kit is designed to function without modifications in MkG lower receivers and mil-spec uppers. Retail pricing for the MkG 8” Barrel and BCG kit is set for $399.95. It is important to note that CMMG is a build-to-order company and supply chain deficits may impact purchase orders.

In addition to 8” kits designed for .45 ACP, CMMG offers kits in 9 mm Luger and .40 S&W with barrel lengths from 5” to 16”. All NFA rules apply. To learn more, please visit cmmg.com.

Latest

Icarry Springfield Sa35 Polished 1
Icarry Springfield Sa35 Polished 1

I Carry: Springfield Armory SA-35 Polished in a Falco C631 Gorham Holster

In our latest episode of "I Carry" above, we're taking a closer look at the details of the new Springfield Armory SA-35 Polished, and we're packaging it with a high-quality leather holster from Falco Holsters, along with a new EDC knife from Work Sharp.

ATF Suffers Major Cybersecurity Incident

On Aug. 27, the Bureau of Alcohol, Tobacco, Firearms and Explosives announced that an outside group had breached its systems in what it termed a "major incident."

The Armed Citizen® Aug. 28, 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.

A Conversation About Gun-Making in America

Recently, a paper titled “The American Tradition of Self-Made Arms" written by Joe Greenlee, director of NRA-ILA's Office of Litigation Counsel,was cited by a court in an important ruling on frame-or-receiver litigation.

The Model 87 Ultra Special: A Rare Survivor of Ithaca's Final Gamble

In the spring of 1990, an 18-year-old received a shotgun he didn't order. The Ithaca Model 87 Ultra Special he got instead was the last gasp of one of America's most iconic shotgun makers.

As Gun Sales Stay High, Violent Crime Hits a Historic Low

According to a recent report from the FBI on national crime statistics, violent crime has decreased 9.3 percent from 2024, marking the largest year-to-year drop since the 1930s.

Interests



Get the best of American Rifleman delivered to your inbox.