Well this is 'here-say' which maybe not what you wanted but it is from a firearms seminar where the MN state pistol champion (okay MN state pistol champ-I think it was bullseye - it was in the early '80's) was giving a talk about all things firearm and told the story of being at a friend's house and as he was leaving the friend said something like 'Oh you gotta try the trigger on my new 1911' and handed him the gun. He points it at the TV (a good bright thing to aim at) squeezes the trigger and blows away the TV. The guys wife was sitting on the couch watching the TV and he said she never flinched but he felt the temperature in the room drop several degrees.
The story unsettled me. If somebody who has shot enough to be a highly rated competition shooter can have a negligent discharge, what chance do I, a casual shooter have of NOT having a negligent discharge?
A question I ask myself to this very day and I never like the answer.