I just found this modification how-to a couple of days ago as my 10 round M&P9 mags were really really tight. I could get 9 rounds into the mag with my Uplula mag loader, but the 10th was really difficult to get in. It also pushed up into the slide and racking the slide was very difficult too. The problem was originally thought to be very stiff springs, but it turns out that the newer mags have a follower that is taller than then ones in earlier versions of the M&P 9 mags. Very simpl