Have you ever seen something that frustrates you solely because you didn’t think of it first? That’s how I feel about the MEAN Arms EndoMag. Why didn’t I think this up? It’s so simple and brilliant. The EndoMag isn’t a mag, necessarily. It’s a magazine conversion kit that allows you to convert your standard Gen 2 or Gen 3 P-MAGs into 9mm magazines. It sounds crazy, but it works. It’s not a permanent conversion, either. It’s a drop-in conversion kit that gives you anywhere from 10 to 30 rounds of 9mm.
The installation is simple. Before you install anything, you need to select your capacity. The back of the mag has a tab with a series of little cuts. If you leave this tab in place, you have ten rounds of 9mm. A simple pair of scissors allows you to quickly and somewhat easily cut the tab to allow for 15 or 30 rounds. Sadly the 2A amendment seems to vary on location, and some states don’t allow you to use 30-round magazines. Either way, these kits are friendly everywhere. Also, since they aren’t magazines, they can seemingly be ordered anywhere with ease.
To install the EndoMag guts, you need to remove the 5.56 guts from the bottom of the magazine. Once those are gone, press the EndoMag through the bottom, and bam, you’re done. Well, nearly. Next, you need to slide the old floorplate on, and now it’s ready to rock and roll.
The Benefits of the EndoMags
If you already own some form of Glock or Colt SMG style lower, you might not see the purpose of the EndoMags. If you don’t have a dedicated PCC lower, then the EndoMags make a fair bit of sense. First, you can use the lower you already use for your 5.56 caliber AR-15. You’ll need a dedicated 9mm upper with either a Glock or Colt Bolt. MEAN Arms also makes a CMMG variant to work with the rotary delayed system as well.
This makes it a good bit cheaper to get into the PCC realm. If you want to build a dedicated rifle, then your standard Muli-Cal lower is a little cheaper than any Glock or other dedicated PCC lower. It keeps things cheap, and while the EndoMag isn’t cheap, it’s on par with most PCC magazines.
This platform also uses the same controls are an AR. Nothing has to be moved or altered to work correctly. The EndoMags also work with your bolt hold open, so you get a last-round bolt-hold open design.
Oh, and not to mention that AR-15 magazines are way more common than Glock, Colt, CZ, and whatever other PCC magazines are on the market. Why is this important? Simple. Commonality means you have options. Options for magazine pouches, mostly. You can get cloth, polymer, dual, single, and beyond. The belts, chest rigs, and pouches you use for your 5.56 rifle can now be used for your PCC.
Since the EndoMags are just 5.56-sized magazines, your training from your 5.56 weapon translates over to your 9mm carbine. Your reload draws, and similar actions are all the same. Every time you train with your 9mm rifle, you are cross-training with your 5.56 caliber rifle.
Do They Work?
That’s the big question! After installing them and loading them, I waited anxiously for the next range day. I did learn that fitting the last two rounds into each of them takes a little force. One downside I noticed is there doesn’t seem to be a mag loader available for an EndoMag converted design.
When fully loaded, the magazines don’t like to fit easily with a closed bolt. They need a firm pat, but they can be loaded against a closed bolt. Since it’s just a P-MAG, it drops free from my gun. If your gun drops P-MAGs freely, it will drop the EndoMags freely.
The big question is all about reliability. Do they work? You’re darn tootin’ they do! I used a basic 9mm upper that uses a Colt SMG bolt. It’s a basic blowback design, and it ate through the EndoMags and their assorted 9mm loads. I went through both basic FMJs and even a mix of JHPs, and it all fed without incident.
MEAN Arms makes the magazines with or without an ejector, and with a Colt SMG bolt, it’s handy to have that ejector for smooth ejection and proper function. My wife and I dumped a little over 400 rounds of various weights and case types. It was primarily brass, but we mixed in some steel here and there. It ran it all.
Reloads and Running The Gun
I will say it was like second nature to reload the gun. Hit the button, the mag drops, and I beer can the next one into the gun. The bolt locks to the rear, so the reload just involves a slap to a bolt release. I have tons of chest rigs and belts designed specifically for the AR-15, so I had tons of gear already on tap for the kit. A Blueforce Gear Ten-Speed chest rig is one of my favorites, and it’s nice to be able to share gear between calibers. The same could be said for my TACO mag pouches and my Wilder Tactical battle belt.
Where The EndoMags Fit
This is one of the rare options that I would have no problems suggesting for a dedicated PCC. I could even see guys in states with restrictions using these for multiple purposes. Maybe you got your hands on some P-MAGs during freedom week, and now you want a PCC? It could be an option. Or maybe your state just hit you with some gun control, and you have grandfathered in magazines.
At the time of this writing, 9mm is a fair bit cheaper than 5.56. It’s got more oomph than a .22LR, and unlike .22LR conversions, this doesn’t change the gun very much. The EndoMags keep the same manual of arms, so it’s easy to argue that this could be a great way to train at a lower price point. On top of the lower cost of ammo, the 9mm rounds are allowed in nearly any indoor range.
You could easily push this into PCC competitions. Reloads are fast, easy to do, and make it easy to shoot quickly and reload quickly. The EndoMags is a great option for shooters looking to take the PCC route in any direction.
Back to 5.56
How hard is it to convert the mags back to 5.56? It’s not hard at all. Push the EndoMag guts out and put the standard 5.56 guts back in. It’s easy enough to convert your AR 15 to an AR9 and nearly just as easy to convert your 5.56 magazines to 9mm. What I would suggest is cleaning the magazines between caliber swaps, as they do tend to get filthy dirty due to the blowback design of AR9s.
The EndoMags is a winner to me. I was impressed at how well they worked and how easy they were to use. If you want to get into the PCC game without adopting an entirely new magazine, then the EndoMags have you covered.
