This same thing happened a few years ago to a young guy who lived in my town.
His girlfriend broke up with him, so he attempted to blow his head off by firing a shotgun through the roof of his mouth.
However, he angled the barrel too steeply in his mouth when he pulled the trigger, thus blowing off a good sized portion of the front of his face, including one of his eyeballs...but no pellets entered his brain.
After 3 or 4 operations, he still looked grotesque.
His girlfriend went back with him (probably out of guilt), but after about 3 months she left him again, probably for the same reason she left him the first time...he was a selfish jerk.
About two years after the shooting incident, the same guy was riding a 4-wheeler while drunk, wrecked it, and was killed due to severe head trauma.
Thus, his death-wish was finally fulfilled. Good riddance.
Unfortunately, there are no videos of either event.