Pippa's right, there are very few stories as literally horrifying as stories of people that tried to blow their brains out and flinched.
One of the easiest (and bloodiest) to find is one of the stories from Joe Kenda's show Homicide Hunter where he responded to a call about gunshots and arrived to find a guy that tried to blow his brains out, aimed wrong, and blew off the entire bottom half of his head. The kitchen was so covered in blood Kenda slipped in it (and went home drenched in it) trying to get the gun and get the guy medical attention.