While I'm in favour of banning most weapons, I don't think *all* guns should be banned. There are valid uses for weapons, such as hunting and thus there is validity in those types of weapons. I'm uncertain on pistols, though I'm rather against many carry laws, especially concealed. But when you bring up larger weapons such as assult weaponry or really any other gun that serves no practical purpose other than attacking another person that I feel should be unconditionally banned for private citizens.
But especially there needs to be careful monitoring of who can buy them. Those with mental problems are one case, as mentioned.