One mag may be bad?

[old fart]

I just bought a G3c and one magazine may be bad. I cleaned the gun and put it back together, started loading the mags. The first one I loaded slapped against my palm and was good, the second one however 7 rounds then it would rattle as if the follower wasn't coming back up to catch the rounds. Number 8,9,10 the mag rattles, go to 12 and its good, remove to number 10 down to 8 and slap my mag and its loose, remove one more to 7 and its tight again. The third mag is also good. I started to load one round at a time and slap my hand each round with the mag. All ammo is tight through 7 but 8,9,10 rattles then 12 is tight but when i remove one its loose again, don't believe it will feed good like this. thanks for any help

 

[JTQ]

Some mags come with some anti-corrosion goo on/in them from the factory. I've experienced a similar hang up, but it cleared once I cleaned the mags. It may not be your issue, but it's worth a try.

 

[Mizar]

If I understand you correctly, one of your magazines rattles when loaded, right? And you never fired it... This is something quite common with double stack magazines, but is does not affect reliability in any way. Like never ever... It's just slightly annoying when you walk down stairs, but that's it.

 

[JohnKSa]

Double column magazines frequently have one or more rounds that are loose and will rattle. That can change depending on how fully they are loaded. I've also run into an issue a couple of times with double column magazines where they will get into a funny bind the very first time they are loaded and used.

Strip the mags and clean them well, especially inside. Wipe the springs with a lightly oiled rag or a silicone cloth, but the inside of the mags should be pretty much dry--or you can apply some sort of dry lubricant, if you wish.

Take the gun to the range and shoot it, making sure that all the mags get fully loaded and emptied a couple of times. If you have problems with one mag, see that it gets a bit more "exercise" than the others.

If you are having function issues by the end of the break-in session, then there's probably a real issue.

Just to be clear, none of this is likely to make the magazines stop rattling. That's a very common feature of double-column mags, even ones that work perfectly.