I know that some of you have experienced cycling problems with these mags. Mine would cycle for about ten shots and then bind up for several shots where I would have to tap on the mag to get it to cycle. I messed with the spring tension with inconsistent results. I finally got fed up and ordered an original side shot mag, which works perfectly with exceptional quality. So then I took the FX mag back apart and lightly lubed the spring with divers silicon. I lubed the rest of the mag everywhere plastic contacted plastic and set the spring at three turns and it is now cycling the way it should. Hope this helps those of you who are having the same problem with consistent cycling.
