This tutorial explains how to modify your m4 mags (STAR MAG brand) to correctly feed into some M4 rifles that do not hold the mag high enough in the mag well.

I was using an AIM M4 and STAR 85 round mid-cap Magazines

Ok so I'm sure that this has happened in the past to some of you. You buy a new M4 and get some mags. In this case I bought STAR MAGS. I was assured by the online retailer that these mags would work in my new rifle. But sure enough, I get the rifle, load up a new mag and I'm firing nothing but blanks.

The problem probably is that your bb release spring (on the mag) is not being pressed at all or enough to release the bb's into the rifle. A lot of people at this point like to proceed with the "ring mod" which is attaching an ~2mm copper ring to the feeder tub in the mag well with super glue (or some other glue). The idea is to let the ring push on the "bb release" button/spring/thingy and release the bb's into the rifle. I did this at first. Problem was, in mid-game my mod fell out (hard to secure such a small piece to a plastic tube that gets banged around a lot for long). At that point my rifle was dead. So I decided to look for a solution that would allow me to mod the magazines instead. This way if one mag mod fails, all I have to do is pull out another mag and I'm good to go. This also allowed me to still use my hi-cap (for target practice, not in game) or use another brand of mag that was actually made to be truly TM compatible (like my friends "Mag" brand mags.

First thing to do, pop the hi-cap that your rifle came with in and make sure it feeds. If it doesn't hen you probably have another problem (don't forget to wind the hi-cap).

Second thing, load up one of your new mags, put it in the mag well and push up on it so that it forces the mag into the mag well just that little extra bit. While continuing to hold upward pressure on the mag fire the rifle. Does it fire now? If so then continue, if not, then you have another problem.

Ok so this was actually just a really simple fix. All I did was put a little sliver of medal in the "lock notch" of the mag, this makes the weapon hold the mag up tighter to the receiving mechanism. Used super glue to secure it. The sliver was ~1mm thick. I actually got the metal from the pump mechanism in a cheap Wal-Mart shotgun, and then just cut it down. Pics below.

The sliver of metal makes the rifle hold the mag up higher in the mag well just a slight amount.

Used these mods for an ENTIRE year. Haven't had one fail yet.