CMMG has announced the release of the MkG45 Guard, a new AR-15 rifle chambered in .45 ACP, fed from Glock magazines. The Guard is offered in five different configurations, and operates on CMMG’s new, patent-pending Radial Delayed Blowback system.
“We set out to engineer an affordable, highly reliable AR chambered in .45 ACP that would use the widely available Glock magazines,” said Chris Reinkemeyer, CEO/CFO at CMMG. “In the early stages of design, we tested out a variety of different operating systems, including straight blowback and direct impingement, but none of those options gave us the reliability we were looking for. We ultimately came up with the design for the Radial Delayed Blowback system and from there, all the pieces started falling into place.”
While the straight blowback system found on most pistol-caliber AR carbines utilizes a non-rotating bolt assembly, the Radial Delayed Blowback system used on the Guard has a bolt carrier group (BCG) that appears similar to that found on a direct-impingement AR-15 but operates completely differently. The rotating bolt is the key to the Radial Delayed Blowback system. It is the act of the bolt being forced to rotate and unlock that slows down the BCG just enough to safely cycle .45 ACP while keeping the BCG and buffer lighter than 9 mm AR-15’s.
Some advantages that result from this new operating system are that it reduces the overall weight of the rifle and simultaneously decreases the felt recoil by using a lighter bolt and buffer. It also opens up the door to run calibers that have historically been too powerful for straight blowback but weren’t suited for direct impingement.
CMMG also put a high emphasis on having fully functional AR-15 controls, including last round hold open. The Guard features an all new patent-pending dual-pinned, fully machined bolt catch linkage. This linkage provides consistent and reliable operation straight out of the box with no need for adjustments or fine tuning. The actuation from this linkage is robust enough that it still uses a standard bolt catch spring.
The MkG45 Guard comes with one 13-round factory Glock 21 magazine. For optimal reliability, CMMG recommends using factory double-stack Glock .45 ACP magazines. Bolt weight kits will be sold separately for those who wish to fine-tune the Guard for +P ammunition or suppressor usage.
The CMMG MkG45 GUARD is available in the following configurations: