Pmags won't fit properly?
 

I'm having issues with the 6 mid-cap Pmags I recently bought for my M4A1. They do fit into the magwell, however they do not lock into place on the mag release, and do not feed into the gun. Any suggestions on possible modifications I could make in order to get them to work?

What gun are they going into?

Javelin M4A1

Real PTS Pmags? Strange.
Probably not sitting high enough? Is mag scratched a little now in the red area on the picture?

The Javelin most likely has very poor QC and bad tolerances, since they are a bottom of the barrel brand.

The area highlighted has the 5.56 x 45 bullet inscription for "realism" I guess. and they do have the PTS marking on the bottom. Apparently PMAGS do work with Javelins, but if that's the case then it should work with mine. However there's a little rise right below the hole where the release catches it, it's a part of the mags design. I believe Taxt may be right, I don't think they're getting high enough into the gun.

After a little bit of close examination, I've fixed the problem. Just had to file down a small part of each magazine, They now lock into place and feed. Thanks!

no PTS markings = crap green label pmags

By the bottom do you mean the dust cover? Or the mag itself?