mthayr
WKR
- Joined
- Oct 16, 2018
- Messages
- 842
Just a PSA for those of you who, like myself have struggled to get AICS .223 magazines (mine are of the steel MDT variety) to feed either the first or last round correctly. I contacted MDT regarding this, and all they would offer is to contact the manufacturer of my rifle (Seekins in this case) for a longer/adjustable mag catch. I reached out to Seekins but hadn't heard back so I decided to take things into my own hands.
The issue has to do with the plastic liner used to take up the space typical SA cartridges normally occupy. Because its plastic, you can't "tune" it like you would typically with steel feed lips. This led me to build a tool to sand the inside of the plastic lips in a geometry identical to the .223 dimensions:
It's simply a piece of 1/4-20 threaded rod with one side filed down some to allow it to screw into the spent .223 round. The nut is simply for grip, and I used spray adhesive to glue some 400 grit wet/dry sandpaper to it. By running this in and out of the magaine, I was able to "tune" the plastic feed lips. For one magazine this was all it took... file (with another empty cartridge in the magazine so as not to damage the follower) a little, test, file some more, test... you get it. A magazine that would never strip the last round now works every time. For another mag, either I filed too much, or the geometry was off from the start. Either way, while I could now get the last round to feed consistently, the first would nose-dive (also consistently). For that I had to disassemble the mag and add some pressure to the front of the feed lips by bending the steel lips in, which, in turn angled the plastic liner lips in as well. Both now cycle all ten rounds reliably.
Point is, if you're having issues using .223 AICS magazines, all is not lost, they can be "tuned" to work in your rifle.
The issue has to do with the plastic liner used to take up the space typical SA cartridges normally occupy. Because its plastic, you can't "tune" it like you would typically with steel feed lips. This led me to build a tool to sand the inside of the plastic lips in a geometry identical to the .223 dimensions:
It's simply a piece of 1/4-20 threaded rod with one side filed down some to allow it to screw into the spent .223 round. The nut is simply for grip, and I used spray adhesive to glue some 400 grit wet/dry sandpaper to it. By running this in and out of the magaine, I was able to "tune" the plastic feed lips. For one magazine this was all it took... file (with another empty cartridge in the magazine so as not to damage the follower) a little, test, file some more, test... you get it. A magazine that would never strip the last round now works every time. For another mag, either I filed too much, or the geometry was off from the start. Either way, while I could now get the last round to feed consistently, the first would nose-dive (also consistently). For that I had to disassemble the mag and add some pressure to the front of the feed lips by bending the steel lips in, which, in turn angled the plastic liner lips in as well. Both now cycle all ten rounds reliably.
Point is, if you're having issues using .223 AICS magazines, all is not lost, they can be "tuned" to work in your rifle.
