Travis Pike for TTAG
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With pistol caliber carbines being all the rage these days, it seems that GLOCK mags have firmly taken their place as a standard in the PCC world. But while they are widely available, affordable, and of high quality, not everyone is on the GLOCK magazine bandwagon.

If you don’t own a GLOCK and want to match your pistol caliber carbine magazines to your handgun of choice, then Matador Arms might have the solution for you. The Mag-X system converts a standard AR-15 multi caliber lower to a variety of handgun magazine platforms.

Yes, the Mag-X conversion includes GLOCK, but they also accommodate SIG SAUER P320 magazines, Smith & Wesson M&P magazines, and, best of all, CZ-75 magazines. I’ve gotten both the SIG and CZ Mag-X models and been taking them for a spin.

What Exactly Is It?

The Mag-X is a conversion block that is essentially the size of a standard AR-15 magazine. It locks into the lower receiver and is held in place by the magazine release.

The downside is the fact that the standard AR magazine release releases the Mag-X adapter block. That means the Mag-X adapter drops out if you press the AR mag release button.

However, Matador was smart enough to include a bolt and washer that lock the block in place, rendering it impossible to release the Mag-X from the magazine well. That can be handy in case muscle memory kicks in and you you press the lower’s magazine release button when your magazine is empty. 

Mag-X pistol caliber magazine
CZ and P320 (Travis Pike for TTAG)

That may lead you to wonder…how exactly, then, do you release an empty pistol magazine?

Mag-X system matador arms
Note the paddle style magazine release button. (Courtesy Matador Arms)

Positioned at the bottom of the aluminum Mag-X adapter, in front of the magazine, is a paddle that releases the magazine when depressed. It allows you to grip the magazine as you press the release and pull it free.

It’s a large ambidextrous paddle that’s actually very easy to use. Couple that with the built-in ejector, and we have a simple, all-in-one package. It’s truly a drop-in design. Installing it is as simple as inserting a magazine.

Mag-X pistol caliber magazine
Notice where the Mag-X engages the inserted SIG magazine. (Travis Pike for TTAG)

The requirements to use it are simple. You need a 9mm upper and a GLOCK-cut bolt. After that, all you need is a standard AR-15 lower receiver, and a heavy buffer might be a good idea.

Does the Mag-X Work?

I used both Mag-X conversion blocks in the same lower and upper. Installation is, of course, straightforward. Because I was swapping between different conversion blocks, I didn’t install the bolt that locks the adapter in place. Again, that’s fine as long as you don’t press the AR’s magazine release button. 

Even so, the standard magazine release was more difficult to press than usual with the adapter inserted, so the block isn’t likely to drop out once it’s installed. It would take a very firm press of the magazine release button to drop the adapter. That’s a good thing. 

Mag-X pistol caliber magazine
Pew Pew (Travis Pike for TTAG)

In terms of reliability, I couldn’t make these things stutter. They ran without issue with all my standard OEM and Mec-Gar magazines. The magazine conversion blocks both locked into the magazines with ease and held them in place without issue.

Mag-X pistol caliber magazine
The mag release position takes some getting used to. (Travis Pike for TTAG)

I blasted through hundreds of rounds, and every round fed, extracted, and ejected without a problem. Note that when using the Mag-X, you lose last round bolt hold open. That’s the only downside I’ve found.

Admittedly it takes a few tries to get used to a new magazine release, but it’s ergonomic and easy to reach and use with some practice. 

Mag-X pistol caliber magazine
Looks a little goofy, huh? (Travis Pike for TTAG)

The standard capacity P320 and CZ-75 magazines may look a might bit goofy poking out a full-sized rifle. The CZ-75 extended 26-round magazine looks a little better and more fitting for a rifle. The utility, though, is hard to beat.

If you own all four adapters — SIG, M&P, CZ and GLOCK — you could use one rifle with all of those magazine platforms. I’d imagine these would be quite handy if you were stocking up for a potential ban on “high capacity” magazines, or if you shoot a multitude of handguns and want to swap magazines with a single rifle or AR pistol. 

Mag-X Price and Availability

The Mag-X blocks retail for $119.99 apiece. They are well-made pieces of gear made of anodized aluminum. Currently, the SIG, CZ, and M&P models are available with the GLOCK model shipping at the end of February. You can check them out here.

Specifications: Mag-X Pistol Caliber Magazine Adapter

Compatible Calibers: 9mm
AR Compatibility: Mil-Spec
Suggested Buffer: 5.8 ounces
MSRP: $119.99

Ratings (out of 5 Stars):

Reliability * * * * *
The Mag-X adapter blocks never fail to go bang. Both blocks I tried functioned perfectly. I only used Mec-Gar and OEM magazines and am curious to see if aftermarket P320 magazines from ETS would work as well. As it stands the Mag-X works perfectly.

Ergonomics * * * *
It’s such a simple system there isn’t a lot to it. It slides into the lower’s magazine well easily, locks in place, and is easy to use. The only downside is getting used to the new magazine release position on such an iconic weapon.

Bang for Your Buck * * * *
This isn’t the only magazine conversion for Mil-Spec AR-15s out there. Plenty of companies make conversions so your rifle can use GLOCK magazines and some of those are $10 to $20 cheaper. However, this is the only conversion I know of that offers S&W, CZ, and SIG options.

Overall * * * *
The Mag-X conversion blocks are very well made, and well designed. They utilize solid construction and open up the number of compatible PCC magazine options. What’s not to love?

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  1. The Stern model ASAP has options for Sig and M&P mags. Plus that one holds the bolt open when the maintenance is empty. Is like to see a review of that one to see how it compares.

    • ASAP? Don’t know how that sneaked in.

      Stern model MAG-ADMP9&40/P320 is one I was considering for Sig P320/250 mags.

  2. I guess it’s okay, but if I wanted a tricycle, I wouldn’t buy a unicycle and add wheels to it. By the time all conversion parts are bought you could probably buy whichever firearm you want.

  3. A purpose built, designed from the ground up pistol caliber carbine makes sense to me.

    This thing does not.

    • It makes sense to me for situations where legally getting a gun is a painful process. In such cases, this is a lot less pain if you want a PCC.

    • There are several uses for these kinds of devices. It’s cheaper than a new complete lower, especially if you’re adding a $100 part to a premium lower. You might have a 5.56 lower that’s an NFA SBR or MG, which is very expensive or untimely to replicate. You might be in a slave state where you have a grandfathered 5.56 gun and can’t get a new PCC.

      • It’s a great concept for those of us who wish to keep a loadout simplified. If I can carry several 25-rd mags all loaded with the same cartridge that will work with both my PCC and my sidearm, it makes things much easier.

        There is no “right” way to loadout, and anyone can do it any way that suits them best. But the Glock mag method is great for me.

      • I think a 38 Super AR would be really cool. Probably a really niche item but regardless. I must be one of about 12 people who think such.

        • Andrew Lias,

          Not at all. I am always thinking about a pistol-caliber carbine that can shoot a “hot” load which will achieve, let’s call it “startling” velocities out of the longer barrel.

          Imagine a carbine with a 20 round magazine shooting the equivalent of a full-pressure (maximum allowable propellant) load .357 Magnum cartridge optimized for a 16-inch barrel. Something like that could launch a 158 grain hollowpoint bullet in the neighborhood of 2,000 fps which would be rather devastating against human attackers.

          And to emphasize my point, ammunition manufacturer Buffalo Bore has such a load which they claim to have chronographed at 2,158 f.p.s. out of an 18.5-inch barrel. Assuming a conservative number of 2,000 f.p.s. muzzle velocity out of a 16-inch barrel, their ballistic spreadsheet indicates a muzzle energy of 1,403 foot-pounds! And even out to 75 yards, that bullet is still zipping along at 1,677 f.p.s. with 986 foot-pounds energy.

          I cannot picture very many human attackers being capable of fighting after taking one such round to the chest — much less after taking two such rounds to the chest — inside of 25 yards.

  4. Increasingly manufactures are (wisely) skipping glock mags, which are an inherently compromised design, and opting for dedicated curved mags that were designed for PCC’s, such as the CZ Scorpion magazines.

  5. I emailed matador a week ago about using these with the cmmg guard rdb design (with integrated ejector) and they said that someone said it worked, (dunno if I believe that as the cmmg need mag to sit higher or lower than glocks, pretty sure at least) you just had to take the ejector out of their block. They also said if it didn’t work they would
    Take it back and refund ya, FYI…

    • With respect to combat, sure.

      If you want something for purely recreational purposes, AR platform rifles chambered for 9mm Luger are a lot of fun and the least expensive centerfire caliber available.

        • Obviously, handguns and rifles chambered in .22 LR are a hoot to shoot as well. If someone wants a bit more oomph, then 9mm Luger is a nice step up.

          Of course .22 LR ammunition is even less expensive than 9mm Luger.

          Different strokes for different folks!

    • Gadsden Flag,

      Don’t forget that many families/households have members are who not physically capable of shooting medium caliber battle rifle platforms. For such families, a pistol caliber carbine is perhaps the optimum choice.

      The longer barrel of carbines provides a nice velocity boost (on the order of 300 fps) to the muzzle velocity of the same cartridge coming out of a typical handgun-length barrel. That longer barrel also provides a longer sight-radius as well as a longer overall package — both of which enable a person of smaller stature to shoot more accurately and confidently.

      And that pistol caliber carbine is surprisingly quiet when shooting for self-defense indoors. That reduces the odds/amount of hearing damage without the added weight, imbalance, and length of adding a suppressor to a battle rifle. (Add a suppressor to a pistol caliber “carbine” with a 10-inch barrel and you have an astoundingly maneuverable, well-balanced, light, accurate, and QUIET self-defense firearm platform for people of smaller stature.)

      Saying it another way, not everyone is a big, burly guy without any regard for their hearing. For such people, pistol caliber carbines are the bee’s knees.

  6. I bought one (and even bought a whole new lower to try it with). It did not fit in the lower, which was milspec. It also didn’t take the ets magazines for the P320 which is what I specifically bought this for. I even emailed them in advance to ask them if it worked. I sent them a video of it not working. I bought two new mags just to make sure mine had not “stretched.” They didn’t lock in empty or full.

    They did offer to refund me, however they didn’t offer to cover shipping back to Canada. So, I can’t even tell you if it works with OEM mags. Just my experience. Buyer Beware.

  7. There is only one company that makes an M&P ar9 lower but it’s an 80% lower. No one makes a complete one that I know of so one of this adapters would be a great alternative. Carrying a side arm and been able to use the same magazine in your rifle would be great. Better than having to carry say 3 17rd 9mm mags and 3 30rd 5.56 mags.

  8. Is there any experience of malfunction with any drop in triggers instead vs mil spec triggers?? There is a video about Sylvan mag adapter not reliably functioning with some drop in triggers. I have Rise 140 in my standard lower, and ‘hope’ this adapter is reliable with it.

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