When MagPul introduced their new polymer PMAGs for GLOCKS, this was an event of great importance to GLOCK enthusiasts. And God knows there are enough of us. There had been aftermarket GLOCK magazines before, but they were famously unreliable trash. To have MagPul, well known for producing reliable, durable, quality polymer magazines for AR-15s and other rifles do the same thing for the most popular self-defense handgun platform, bar none, was a big deal. The MagPul GLOCK PMAG costs half a factory GLOCK mag, and works. The first question out of the mouths of everyone to whom I mentioned these magazines was, “Will they take the various aftermarket extra-capacity floorplates?” The answer was no, the PMAG uses a very different floorplate-to-mag-tube interface system. Enter Arrendondo Accessories. MagPul is famous for doing great polymer magazines; Arredondo is famous for doing great extra-capacity magazine floorplates.

Arredondo’s extra-capacity floorplates are very distinctive; there is a consistent design philosophy at work here. The actual designs may differ in their particulars, but they will always be (a) simple, (b) secure and (c) durable.

A bit about that “simple” part. When I say that, I mean the designs will be elegant with no excess foo-foo about them. And while straightforward, the way the floorplate mounts to the mag tube will be designed so it absolutely will stay on the gun. Some aftermarket floorplate designs are famous for coming apart during use: You’re firing the gun, suddenly the magazine “explodes” and all the ammo in the magazine just sheets out the bottom of the gun. That never happens with Arredondo floorplates. There are other extra-capacity magazine floorplates that are prettier, they’re made of aluminum in different colors (ooh!) and the Arredondo floorplates are made from no-BS black polymer. But there is nothing that works better.

The Arredondo GLOCK PMAG floorplate is intended to give a magazine meeting the overall-length rules for USPSA Limited division. This is fine, since it also results in a magazine not too long for realistic concealed carry. This is a +5 magazine floorplate; it ups the capacity of a GLOCK 17 mag from 17 rounds of 9mm to 22.

In general, when you fully load any magazine, you want to have approximately half a cartridge diameter of spring compression left over, so the magazine may be snapped easily into the gun with the slide forward. Also, if you have very little or no spring compression left over, the top cartridge in the magazine will wind up pressing so hard on the underside of the slide, that retards slide momentum so much, you’ll fire the chambered round and the top cartridge in the magazine will fail to feed.

I must admit to a bit of surprise when loading the Arredondo floorplate equipped PMAG to find, I’m not going to say “no” but very little spring compression left over. I was further surprised, however, to find that even with that little spring slack, snapping the magazine into the gun with the slide forward was easy. You don’t even have to slap it in particularly hard. I can only theorize this is because the all-polymer PMAG tube “gives” and expands more than an all-steel tube (or even a standard GLOCK mag which incorporates a steel liner along most of its interior), allowing the mag stack to compress when the magazine is inserted into a slide-forward auto-pistol. Taking the Arredondo/MagPul hybrid PMAG to the range, I found out it will indeed feed the top round out of the magazine after firing the chambered round. I further theorize the polymer feed lips have a greater lubricity factor versus steel, allowing rounds to feed more easily.

As you would expect from an Arredondo extra-capacity magazine floorplate, the mounting system for the GLOCK PMAG is elegantly simple and rock solid. Inside the mag tube, an L-shape subfloorplate hooks onto the bottom of the mag spring. (A slightly longer than stock mag spring, to go with the slightly longer magazine once the Arredondo floorplate is installed, is of course supplied with every Arredondo PMAG floorplate.) This subfloorplate is tall enough that, when it’s in its normal, inside-the-tube, fully down position, it absolutely prevents the floorplate from coming off the magazine. To remove the floorplate, take some sort of long, thin punch, insert it through the hole in the floorplate, depress the subfloorplate until it’s below the end of the mag tube, at which point the floorplate can be pulled to the rear and off the magazine. Unlike the factory GLOCK mag, the floorplate on a PMAG pulls to the rear for removal, not toward the front.

The standard, out-of-the-box subfloorplate on a GLOCK PMAG features a raised button that inserts through the floorplate hole and comes up even with the “top” (or, depending on how you look at it, bottom) of the floorplate, with a hole in the center of the button to give purchase for a tool (punch, bullet tip, ink pen, whatever) when depressing the subfloorplate for disassembly. Again, I was surprised to look at the Arredondo PMAG subfloorplate and see that’s not the case here. While there is in fact a dimple to give a purchase point for a disassembly tool, the subfloorplate itself has no raised button; rather the dimple is recessed into a flat subfloorplate. This means when the subfloorplate is in place and the floorplate is slipped over it, you have to look down inside the hole to see the subfloorplate.

Honestly, at first I didn’t like that. While the logical part of my brain realized it didn’t matter, it didn’t affect functionality at all; aesthetically I preferred the “even” appearing MagPul subfloorplate. The human eye likes symmetry. When I asked Ralph Arredondo why he didn’t raise that portion of the subfloorplate into a button that would fit through the floorplate hole, his reply was, “It wasn’t necessary.” Fair enough. With more experience, I have to admit I actually like the way the Arredondo PMAG floorplate/subfloorplate assembly looks in this regard. But it did take some getting used to.

I have since integrated the PMAG/Arredondo magazine into my regular stock of GLOCK mags. I have shot it many times on the range during personal practice sessions. It just works. As you would expect from a MagPul PMAG. As you would expect from an Arredondo floorplate.

So there you have it. MagPul: great polymer magazines. GLOCK: the most popular selfdefense/ carry gun in America, if not on the planet. Arredondo Accessories: maker of elegantly simple, functional, durable, no-BS, they-just-flat- WORK aftermarket extra-capacity magazine floorplates. Put them all together, you’ve got something really special.


Written by Duane Thomas | Self-Defense-Handguns.com

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