CMMG Announces MkG45 AR-15 Rifle

by
posted on April 25, 2017
cmmg_guard_lede.jpg

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:

MkG45 Guard T:
Barrel:
16.1” 1:16 Twist, Medium Taper 4140 SBN Barrel
Muzzle: CMMG SV Brake, Threaded .578-28
Handguard: CMMG RKM11
Furniture: A2 Pistol Grip, M4 butt stock with 6-pos mil-spec receiver extension
Receivers: Billet 7075-T6 AL Lower, Forged 7075-T6 AL Upper
Trigger: CMMG Single Stage Mil-Spec style trigger
Weight: 5.6 lbs (UNLOADED)
Length: 32.5 (STOCK COLLAPSED)
MSRP: $1299.95

MkG45 Guard DRB:
Barrel:
16.1” 1:16 Twist, Medium Taper 4140 SBN Barrel
Muzzle: CMMG SV Brake, Threaded .578-28
Handguard: CMMG RKM14
Furniture: Magpul MOE Pistol Grip, Magpul CTR stock with 6-pos mil-spec receiver extension
Receivers: Billet 7075-T6 AL Lower, Forged 7075-T6 AL Upper
Trigger: CMMG Single Stage Mil-Spec style trigger
Weight: 5.8 lbs (UNLOADED)
Length: 32.5 (STOCK COLLAPSED) 
MSRP: $1399.95

MkG45 GUARD PDW:
Barrel:
8” 1:16 Twist, Medium Taper 4140 SBN Barrel
Muzzle: CMMG SV Brake, Threaded .578-28
Handguard: CMMG RKM7
Furniture: Magpul MOE Pistol Grip, Magpul MOE stock with 6-pos mil-spec receiver extension
Receivers: Billet 7075-T6 AL Lower, Forged 7075-T6 AL Upper
Trigger: CMMG Single Stage Mil-Spec style trigger
Weight: 5 lbs (UNLOADED)
Length: 25 (STOCK COLLAPSED)
MSRP: $1349.95

MkG45 Guard PDW Pistol:
Barrel:
8” 1:16 Twist, Medium Taper 4140 SBN Barrel
Muzzle: CMMG SV Brake, Threaded .578-28
Handguard: CMMG RKM7
Furniture: Magpul MOE Pistol Grip, CMMG Pistol receiver extension
Receivers: Billet 7075-T6 AL Lower, Forged 7075-T6 AL Upper
Trigger: CMMG Single Stage Mil-Spec style trigger
Weight: 4.7 lbs (UNLOADED)
Length: 24" (STOCK COLLAPSED
MSRP: $1299.95

MkG45 Guard DRB2:
Barrel:
16.1” 1:16 Twist, Medium Taper 4140 SBN Barrel
Muzzle: CMMG SV Brake, Threaded .578-28
Handguard: CMMG RKM14
Furniture: Magpul MOE Pistol Grip, Magpul CTR stock with 6-pos mil-spec receiver extension
Receivers: Billet 7075-T6 AL Lower, Forged 7075-T6 AL Upper
Trigger: Giessele Automatics SSA
Weight: 5.8 lbs (UNLOADED)
Length: 32.5 (STOCK COLLAPSED)
MSRP: $1599.95

 

 

Latest

Forehand & Wadsworth British Bull-Dog right-side view nickel-plated gun revolver with black grip
Forehand & Wadsworth British Bull-Dog right-side view nickel-plated gun revolver with black grip

I Have This Old Gun: Forehand & Wadsworth British Bull-Dog

Many eagle-eyed NRA members viewing the 1993 Western “Tombstone” no doubt recognized the Forehand & Wadsworth British Bull-Dog so deftly welded by actress Joanna Pacula, portraying Big Nose Kate, during a contemptuous card game between Doc Holliday and Ed Bailey.

Medal Of Honor Marine Receives Henry Repeating Arms Tribute

Henry Repeating Arms presented a Spirit of the Corps 250th Anniversary Tribute Edition rifle to Maj. Gen. Livingston for going above and beyond the call of duty on May 2, 1968, during the Battle of Dai Do in Vietnam.

Preview: Duramag 1911 DS Magazines

Duramag’s 1911 DS Magazines are compatible with numerous 9 mm Luger-chambered 2011-style handguns on the market.

Colt Monitor: The FBI’s “Fighting Rifle”

In the years between the World Wars, a rare variation of the Browning Automatic Rifle proved its reputation as an effective, devastating automatic rifle for combat between the country’s lawmen and its outlaws.

The Armed Citizen® May 19, 2025

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

Report Shows Inventory, Prices Have Dropped At Firearm Retailers

Nearly all gun and related gear inventories at retailers dropped in the last 12 months. So have most prices paid at the counter, according to the year-over-year comparison detailed in the latest RetailBI report.

Interests



Get the best of American Rifleman delivered to your inbox.