There are definitely those weapons that are legitemately for the use of a hunt(especially in times of crisis which may be approaching) - But in general; claiming rights to a weapon designed for the function of killing large amounts of humans because you can't think of any decent reason not to... just doesn't cut it. Self defense, perhaps. But when you own a weapon, and I have absolutely no reason to trust you with it, what good reason can you give me right now that you need one? Either I find myself a paranoid, or you find yourself a gun-nut in the presence of a cautious pacifist. How can you prove to me that once you own this weapon you will never, ever, use it?
