I recently bought 10 new production P'Mags and have been quite impressed untill today when I made a discovery. I load my heavy bullet 69 grain Sierra SMK's a little long to try to conserve as much case capacity as possible for powder. This has never been a problem with the GI mags because as long as they fit in the mags they work but I had numerous failures to feed with these rounds in the PMags. So if you reload make sure you do not go over standard length or they will not work reliably. This is not a criticizm of the Pmags as they work great with standard ammo as intended but if you like to experiment with the length of your reloads or use commercial reloads make sure they do not exceed SAAMI length specs. Or use GI mags.