Every time we have a new recruit class, I see a few new failures that I either didn't consider or hadn't seen before. We have issued M&P9s since 2008, overall it has been an outstanding duty weapon. Here's a few:
-trigger hinge pin walking out
-extractor breakage
-mag floorplate failure
-rust (officer maint. failure)
-roll pins splitting
-recruit installing the guide rod backward during the mad-minute drill, had to take that one apart with a rubber mallet. I still have no idea how he got it together...
When we first got our M&Ps, S&W accidentally sent us a batch with .40 cal slides and 9mm barrels. We were baffled that all of our brass was hitting us in the forehead, it wasn't until we sent them back that they realized that the slides and extractors/ ejectors were wrong. It was funny afterward, but really aggravating at the time. I can say that most officer's love this pistol, I just wish it had a more definite trigger reset.
What issues have you guys run into?
Mark