Originally Posted by TokyoSeven
Some users have noted that there can be feeding issues with KA brand M4 magazines but the issue is remedied by slight filing of the mag feeder. I have not experienced any issues myself but a small amount of people have.
This seems to be an issue with their 120 rnd midcaps more than their 68 rnd low caps. Not sure of the reason for this exactly, but it seems to be the case for the most part.