I agree with AaronM using a gun is a way to change someones course of action.
But these are great. Instead of having a weapon where you could simply injure and scare some 15 year old kid fucking around on your property (not every self defense situation is against some giant, PCP crazed psycho killer-rapist) and then just hurt your 10 year old when his friend accidentally shoots him, these bullets can insure both die horrifically with no second chance.
