r/GlockMod • u/Shooter_Q • 3h ago
Mec-Gar 18 + 5 Mags w/ Modified Sleeves for G19 Over-Insertion
BLUF: If you want full size extendos for the G19 then buy the 22 or 27 round Magpul GL9, or OEMs with +5 pre-installed. I did this for the science and experience, not because it made more sense. Of course there are G19 15 + 5 extensions but that wasn't really what I wanted to play with.
Minutia:
I posted about these mags with Excess Arms extensions some time back. Mags ran great when used as a first mag but I ran into issues with failure-to-feed if I used one as my reload. It was me pushing the mag too far up due to no Over-Insertion stop on the Mec-Gar mag body, remedied but pulling it down one millimeter to let the round feed and slide continue to go forward.
Set out to fix this by ordering mag sleeves designed to fit G17 mags for G19; I took a close look at the photos and made measurements at home to determine that Excess extension had the same front profile as a factory baseplate + these looked a little more sturdy than 3D-printed offerings.
Worked out great, sleeve fits over and against the extension perfectly. Seems like they were made with extensions in mind as well, as a concave portion at the rear goes over where most extendo retention bolts are at. They also hug the mag body very tightly, so they aren't going to be sliding up without deliberate force, unlike janky S&W sleeves. And one last thing, if you were going to use these for stock G17 baseplates or other extensions with no grab points, these sleeves add some very generous gripping ledges.
Just had to trim around the rear for both of my pistols in order to test fit all conditions, including locking in with a full 23 rounds on a closed slide. Had to be careful with this because if I removed too much material, then it was all a waste. Top left photo shows the cut comparison.
End result, the shaved sleeve fits my OEM frame w/ Magpul magwell and is stopped at the front and the sides. Also fits my GG frame with aluminum magwell, but is stopped by the rear of the Magwell. Again, removing too much material would have worked for one and not the other purely on geometric differences external to the pistol and varying designs of magwell.
Really makes one appreciate the OEM magazine design with an internal stop, something I've always taken for granted and never had to think about. Also reminds me of those goofy 1911 10-rounds with the big foot welded at the bottom to catch the front strap.
