So I've just got my new g and p with a magpul lower receiver and the pmag it came with feeds perfectly but my socom gear troy battle mags will only feed 1 or 2 before it just dry fires, just to confuse me even more though my g and g high cap feeds perfectly as well. I've had to puts one tape on the side of the socom gear ones to stop them dropping down lower on the receiver
I've also fitted a madbull ultimate hop unit but this shouldn't make any difference should it?