Itraded for the full size 320 in 40 S&W couple of years ago and have never had a problem of any sort. Just for fun I finally broke down and got the 357 Sig barrel for it. Wow, I never realized until doing a little study that I now have a 14 round semiautomatic capable of ballistics that beat my .357 Mag. wheel gun.
Never had an issue with my P320 full size tacops (9mm), Compact 9mm and sub-compact 9mm. The P320 I actually run the sub-compact x-change kit on it. Between both the compact and sub I have over 2000 rounds. The P320 is a just a great gun.