This has been a bit of a saga over the last few years. There have been numerous reports (To date >100) of P320s firing in the holster unintentionally, or to use the current term, un-commanded. Many of these have involved LEOs. Given that the P320 has a very light short trigger pull, many of these incidents may well be due to something interacting with the trigger either through user dumbassery, questionable carry practices, improper holsters and the like. However, there have been some incidents where this is simply not a viable explanation, such as the Camp Foster incident. This incident involved a M18, and it was difintively determined that the pistol was properly seated in the holster, there was no user interaction with the weapon at the time of discharge, and the manual safety was properly engaged. Also somewhat disconcerting is the FBI report that was issued following an examination of a Michigan State Police 320 following an un-commanded discharge.
MSP-M18-Pistol-Evaluation_FINAL_Redacted_Outdoor_Life.pdf
I personally own three 320s, and I have personally had no issues with any of them, however for now they are on the bench, and I am currently carrying a S&W M&P M2.0. For those who are interested, there is a very good thread on Pistol-Forum that covers the issue in depth. https://pistol-forum.com/showthread.php?43653
Note* For some reason clicking on the link doesn’t seem to work for the Pistol-Forum thread, but if you copy and paste the URL it will take you there.