The CMMG Guard – .45ACP AR15!

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April 18, 2017
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Pistol Caliber Carbines are all the rage right now, but until recently, AR15 PPCs have mostly been chambered in 9mm.  However CMMG has just brought their new 45ACP Guard AR15 to market, and it’s pretty slick.

CMMG MkG45 GUARD

CMMG MkG45 GUARD in the new Titanium Cerakote

After shooting some pistol caliber carbines in the past I’ve wanted one in 45ACP because suppressing them is fun, and suppressing a 45 is even better.  Granted it’s not always as quiet as a 147 grain subsonic 9mm, but it packs twice the wallop.  However, the 45ACP isn’t easy to run in a straight blowback operated rifle due to the pressures so we haven’t seen them in mass production, until now.

Inside of the Guard

Inside the Guard

CMMG has some pretty innovative engineers that tend to think outside the box.  A few month’s ago they brought us the Mutant AR15 that not only accepts AK47 magazines and 7.62×39 ammo, but they redesigned the entire system to give it more strength and reliability.  Then they tweaked the .458 SOCOM Anvil rifle in the same manner.  Now, they created a way to shoot .45ACP from an AR15 with a few improvements.

The cornerstone of the Guard is the Radial Delayed Blowback system that utilizes what looks to be a mostly standard AR15 bolt carrier group.  The only purpose of the bolt key is to give the bolt charging handle something to snag.  Everything else works as an AR15 action, except the cartridge blowback pressure itself unlocks the bolt instead of a gas system or piston.  This delays the operation just enough to allow the bolt to safely and reliably cycle and in turn keeps the bolt and buffer weighing less than 9mm straight blowback systems.

The Guard's Radial Delayed Blowback Bolt System

The Guard’s Radial Delayed Blowback Bolt System and weighted kit for load adjustments.

In fact the bolt system weighs so little that you can buy an extra weight kit in order to tune the rifle for your intended use and loads.  For instance, I used the 2 oz. weight since I was running suppressed.  If I was shooting +P loads I might try the 3.5oz weight pictured above.

The Guard takes Glock 21 magazines. 13 rounds of carries over twice the lead of a 30 round 55 grain 223 magazine.  The Guard has a patent pending dual-pinned fully machined bolt catch linkage that keeps the bolt open after the last round fired.  Yet it still uses a standard bolt catch.

Guard's Machined Bolt Linkage

Guard’s Machined Bolt Linkage

As soon as I had the Guard home I removed the cool 45 caliber muzzle brake and screwed on my Bowers ASP suppressor. 230 grain pills are naturally subsonic so we can make it movie quiet with a can.  And it was.  It’s actually quieter for the bystanders than the shooter since my ear would pickup the recoil spring twang.  The rifle was noticeably quieter than my pistols due to the extra volume that the barrel holds.  In fact I didn’t even wet the “wet only” ASP suppressor.  Pretty neat for just 5 oz!

Guard with Bowers ASP and Meopta 1-4x

Guard with Bowers ASP and Meopta 1-4x

Accuracy was impressive as well.  I’ve tested a few 9mm PCC with disappointing results, but the Guard was splattering one spot on steel at 100 yards.  Granted there was a little drop from 25-100 yards.  But this could be a direct competitor to a 300BLK rifle, especially when the 45 ACP ammo is naturally subsonic and more affordable than subsonic 300BLK.

The Guard is retailing for $1,300+ and has several options, even pistol and NFA SBR versions.  You can find all the details over at CMMGInc.com.

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