There are indeed documented incidents with this gun firing on its own, SIG blames it on defective firing pin spring...
I would not trust this gun, between the drop firing issue and this issue, this is not a weapon I would own.
https://www.minutemanreview.com/sig-p320-safety/
Perspective from both sides of the issue:
“Not much detail is provided in any of those other claimed incidents, but a few stand out. For instance there’s Lieutenant Thomas Ahern who was was “performing a routine function (test) of his P320 when it fired at him without any force towards the trigger, resulting in the bullet impacting his left thigh.”
Who function tests their firearm 1) with a round in the chamber, and 2) when it’s pointed at an extremity?
And then there’s Gunter Walker, a civilian, who says his P320 fired on its own “when he placed the weapon down on his nightstand, shooting him through the palm of his left hand.”
Have you ever put a handgun down with your palm in front of the muzzle? Would you?
There’s also an un-named Texas gun shop manager who says a P320 fired “as he cleared the weapon, blowing off one of his fingers. The weapon was out of battery when it fired.”
First, clearing a loaded firearm with a finger over the muzzle doesn’t exhibit even cursory adherence to the Four Rules. Second, pardon us if we’re more than a little skeptical that the P320 in question — or any other handgun — fired when it was out of battery.
Again, these are examples the plaintiff in this case is using to support his claim that the P320 is prone to “un-commanded discharges.”...
...Then there’s the fact that the branches of the military have put the P320 design through their own batteries of testing and found it duty worthy. They have hundreds of thousands of P320s in regular service now and, despite a search, we couldn’t find a rash of reports of soldiers claiming their pistols are firing on their own.”
https://www.thetruthaboutguns.com/about-those-sig-p320-lawsuits/