There's no science to it, just plain common sense. I think that we need to adopt a more adult attitude about firearms that should be reflected in responsible gun laws. There is no reason for anyone not in the military or police service to have weapons designed for use in combat. Likewise, the public obsession over handguns for personal protection is beyond reason. Unless you are a qualified expert, or police-trained in handling small arms, it is a mistake to think you will be safe in you home with a loaded pistol. (You are more likely to shoot yourself than ward-off anyone intent on doing you harm.) If you must have a gun for protection, then get a 12 gauge, double-barrel shotgun, load it with medium bird-shot and keep it ready to hand. For most people, you are probably better protected with a cell phone with one-touch dialing for emergency calls.