Something is not right about this story. When I was a kid, I once had some .22 Long Rifle shells in my jacket pocket along with a 9V battery. A shell went off when it shorted across battery’s contacts. It just made a muffled, but sharp “pop”, and barely caused my denim jacket to move at all.
I'd think you're more likely to be hit by the casing than the bullet.
Son's IQ jumped a few points that day.