I just bought a G33 several weeks ago. I have a couple of magazines with the Pierce +1 and a couple with the Pierce +2 grip extensions. If I load seven or eight rounds or more, then after the first shot, it fails to feed the next round. The round will jam up against the bottom of the feed ramp. If I then pull the slide back in an attempt to get it to load, it still will not load. In fact after just trying it once or twice, I noticed the round was ruined because the bullet had been pressed into the casing making it too short. Any advice? Is it the Pierce Grip extensions causing this by making the springs too weak? I never shot it with the standard magazines because I changed them out as soon as I got the pistol. I am shooting Lawman TMJ and Speer Gold Dot ammo. I have fired about 300 rounds with this pistol. Thanks for any advice.