Here's what one type of typical exchange with an anti-gunner looks like.
"Owning a gun isn't a natural human right."
Yes, it is. Self-defense (and possessing the proper tools to exercise it effectively) is the most fundamental human right there is.
"If guns were only used in self-defense, I would agree."
There is nothing in the world that is ONLY used for good. If good people give up their guns, you've eliminated all the benefit.
"Every other country in the world disagrees."
Did no one ever ask you "If all your friends jump off a cliff, will you do it, too?" Following "everyone else" is often the dumbest possible thing you can do.
"But I have the right to not be shot."
Yes. And it's your responsibility to exercise your right of self-defense to try to make sure it doesn't happen. Maybe even help others also not get shot. No one has the right to shoot you as long as you aren't violating anyone, but that's what makes a bad guy a bad guy: they do things they have no right to do (like shoot you or make up legislation) and violate you in the process. It is your responsibility to prevent them from doing so. If you refuse to take responsibility, don't blame others when you face consequences you don't like.