Is there any chance your thumb was resting on the slide stop, keeping it from activating?
I have 2 M&P 9's with over 3000 rounds thru them, combined, and have not had this problem with either one.
I have had some problems with the slide dropping by itself, without chambering a round, when I perform a reload. I was in the same squad with Ernie Langdon at IDPA Nationals and he diagnosed it as a shooter induced problem. He said I am slamming the magazine in too hard and causing the top round in the downloaded magazine (10 rds in a 17 rd mag) to bounce down just when the slide goes forward and it fails to pick up the first round.
--Lin
I have 2 M&P 9's with over 3000 rounds thru them, combined, and have not had this problem with either one.
I have had some problems with the slide dropping by itself, without chambering a round, when I perform a reload. I was in the same squad with Ernie Langdon at IDPA Nationals and he diagnosed it as a shooter induced problem. He said I am slamming the magazine in too hard and causing the top round in the downloaded magazine (10 rds in a 17 rd mag) to bounce down just when the slide goes forward and it fails to pick up the first round.
--Lin