Shot about 125 rounds during a course this evening. Training used 2 mags loaded 8-rounds each. I rotated 3 Wilson 47d mags. At least 12 - 15 FTF. Most were either the first round or the last. A few of the FTF with the last round the slide actually locked open so I dropped the mag and a loose round fell with it. I've never had that problem before in over 1200 rounds. It got to the point where every other full mag would not load the first round into the chamber. I watched the slide release and there wasn't a jam, the round just sat there in the mag. FTE usually occurred with the last round. One stovepipe was so bad the slide was jammed as well as the mag. The instructor took it to the gunsmith at the shop to remove the brass. So, I've got some reading to do. I would suspect extractor tension for FTE. The Wilson mags have less than 250 rounds each. I recently went from a 16# Wolff recoil spring with Springfield ILS and mainspring to an 18.5# Wolff with a Wilson mainspring housing running a 23# main. I fired about 150 rounds of 230 FMJ and 230 JHP and some 230 +P JHP with no problems after the switch. No clue as to the FTF problems.