I was at an IDPA match yesterday. There was one participant who had an M&P 9mm and was going through his stage. I have never seen a gun malfunction so much. Stove top, failure to feed, would not go into battery and a few other things....and there was a maximum of 31 shots. Fortunately, he had enough ammo to clear everything and finish, but wow.
Now in all fairness, his gun did not malfunction at all the rest of the match, but it was not a pretty sight when it did so many times in one stage.