How can you have the money and passion for weaponry to get a ballistic vest yet lack the knowledge and gun discipline to shoot live weaponry at it while wearing? Even if the vest was resistant to that particular shot, at the distance you would have to be wearing it to be effective at there's a good chance the person could miss (compounded by the fact anyone decent enough of a shot would have the weapon discipline to not do this in the first place).
If you want to waste your ballistic vest by shooting it for shits and giggles, buy a watermelon or something.