It's a mute point if you can hit what your aiming at.    It doesn't matter how much armor someone is wearing if you can hit them in the head at 500 meters plus.    Take any common centerfire (match) cartridge in a reliable accurate firearm and learn to shoot it with the upmost precision. Once you get to the top of your game teach your family the same and you will be an adversary the enemy stays away from.     If they do attack your family they will be yesterdays news.