MEAN Arms EndoMags for CMMG Guard

First Generation of Endomags had two issues for me.

  1. If fully loaded to 30 rounds there just wasn’t enough give to seat the magazine with the BCG in the forward position.
  2. I have (2) 8″ CMMG Guard barrels, the first one has a dual M4 feed ramp extension which I’ve used for most of my testing.  The second barrel has a single feed ramp extension for Glock mags.  The second one had some intermittent feeding issues if using my preferred buffer/spring/tube arrangement.  However, if using a stronger spring and lighter buffer it would work but it wasn’t as smooth.  The malfunction was that rounds would jam at a 45 degree angle while trying to feed.  The new design has like ‘wings’ that go over the feed ramp to prevent rounds from doing that.  However, I had already contoured my second barrel to be like my first barrel and it is fine now.

The new generation of magazine resolves both issues.  Picture below taken by ‘J4c3′ shows the Gen1 on the left to the Gen2 on the right,   Notice feed ramps seem more conical and the ‘wings’ that go over the feed ramp.

When the Gen1′s came out, if you got one with the built in ejector for a straight blowback AR, you could just modify them to work with the CMMG Guard but now with the improvements of the ‘wing’s over the feed ramp and the more conical feed ramp, you want the CMMG specific Gen2′s as the straight blowback MEAN Endomags don’t have those features.

Also, I contacted MEAN Arms and they told me that these are identical to what CMMG is marketing as their ’9 ARC’ mags.  They make them for CMMG so rest assured you are getting the same thing whether you buy from MEAN or CMMG.endomog-gen1-vs-gen2-2


In regards to loading a full 30 round mag on a closed bolt, it was doable but still quite a bit of force.  More than a 9mm Colt mag would be so I cut it above the limiter notch as seen below.


Side view shows that where I cut it is now above the bottom of the follower.  It now requires less force to seat a fully loaded mag.  About what you have on a full 30 round 556 PMAG on a closed bolt.
Also note the white paint from a Sharpie I used to mark the spring.  I’m using windowed PMAG’s and this is close to where it needs to be.  I do a lot of testing with 10 rounds loaded and I can quickly see where it is at with the paint on that coil.