The Ultimate Firearms Destination for the Gun Lifestyle

Preview – CMMG Mk9 PDW – Acronym-Tastic

At RECOIL, we review every product fairly and without bias. Making a purchase through one of our links may earn us a small commission, and helps support independent gun reviews. Learn More

Photos by Kenda Lenseigne

CMMG’s Mk9 PDW is Both Versatile and Fun to Shoot

We’ve always been a little skeptical of AR pistols. They’re too big to really work like pistols and, thanks to the NFA, will always fall short of their potential as rifles — unless you’re willing and able to get a tax stamp. So when CMMG’s Mk9 PDW arrived we weren’t quite sure what we were going to say about it. Then we shot it.

Back when this gun was originally launched, all was good in the land of stabilizing arm braces. Everyone knew what they were supposed to do, as well as what they could do, and the ATF treated everyone like adults and left well enough alone. That delicate balance was thrown into upheaval and at this point, it’s kind of irrelevant whether you want to blame the pencil-pushers in West Virginia or the tidal wave of mother-may-I letters sent by gun owners trying to prove a point. What matters is how we proceed from here. For many shooters, their SB-15-equipped pistols will now become safe queens. Others, who had previously been on the fence about buying a weapon pre-equipped with an arm brace, will likely throw up their hands and put their pennies toward some other purchase.

We bring this up because even though we had a chance to equip the Mk9 with an arm brace and shoot it from any position we damn well pleased, we didn’t. In retrospect, we’re kinda glad for this as it demonstrated that rifle-pattern pistols don’t have to be abandoned wholesale just because of some bureaucratic bickering over accessories.

PDW-02 PDW-03

Nuts and Bolts

The Mk9 is CMMG’s entry into the pistol-caliber AR market. It’s available as a factory SBR, but the more easily accessible version is the pistol variant. The only difference between the two is whether it ships with a buttstock or a pistol buffer tube. The Mk9 pistol sports an 8.5-inch nitride-treated barrel made from 4140 chromoly steel. Said barrel is sheathed in a 7-inch KeyMod handguard with a continuous top rail. The pistol grip and trigger guard are of Magpul’s ubiquitous MOE line. All controls and small parts (trigger, fire control selector, charging handle, etc.) appear to be factory standard. The muzzle device is an A2-style birdcage. The one included magazine is a 32-round “stick” magazine patterned off the old Colt SMG mags. While the Mk9 only comes with one magazine, spares are available on the CMMG website at a wallet-friendly $20.

Our test gun was not equipped with any sights, so we used that long top rail to try out a few red dot optics, such as an Aimpoint Micro, an EOTech, and the Hi-Lux Micro Max B-dot seen elsewhere in this issue.

CMMG was wise enough to use a receiver endplate that has small sling loops, like dog ears, on either side of the buffer tube. The awesome folks at Echo93 sent along one of their two-point Seat Belt Slings, which was attached right quick. As the name implies, these are simple two-point slings with an HK-style CLASH hook (or QD swivel) at each end that are made out of seatbelt webbing. The seatbelt webbing provides a wide, comfortable sling that’s also particularly low friction when compared to similar designs of webbed cotton or lower-grade nylon webbing.


For the rest of this article, subscribe here: RECOIL Issue 22

Enter Your E-Mail to Receieve a Free 50-Target Pack from RECOIL!

NEXT STEP: Download Your Free Target Pack from RECOIL

For years, RECOIL magazine has treated its readers to a full-size (sometimes full color!) shooting target tucked into each big issue. Now we've compiled over 50 of our most popular targets into this one digital PDF download. From handgun drills to AR-15 practice, these 50+ targets have you covered. Print off as many as you like (ammo not included).

Get your pack of 50 Print-at-Home targets when you subscribe to the RECOIL email newsletter. We'll send you weekly updates on guns, gear, industry news, and special offers from leading manufacturers - your guide to the firearms lifestyle.

You want this. Trust Us.

Add a comment

Your email address will not be published. Required fields are marked *

Subscribe to the Free