On two of my three magazines, I've experienced the following: When firing, the floor plate on one mag "unlocked" itself and slid forward.

Fortunately, the mag release kept it from coming all the way off and spewing spring and ammo out the bottom. I corrected this problem by slightly bending the spring follower just above the floorplate upward toward the spring. On my other problem mag, the floorplate actually slid backwards (how the front lip of the floorplate cleared the bottom edge of the mag I can't figure out!

) and jammed the mag in the grip. I shot the gun empty, then I had to use a wood dowel and mallet to tap the front floorplate lip back over the front of the magazine.
Anyone out there have similar problems with mags?