Ask questions in addition to stating facts.
If you can ask why five times, you might be able to make them realize by themselves that their own logic is flawed, instead of you telling them it is.
Ackhuyally rarely works and often works against its purpose, even if you are correct.
It isn’t easy, but if you can steer the conversation in a way where people have to rationalize their own point of view, you might get somewhere.
Also don’t get mad, and accept that some people are just so set in their ways that you cannot change their mind, and it usually isn’t worth burning bridges over.
As an example, but not relating to firearms, I’m sure you can relate to this type of discussion:
Just the other day I had a discussion on nuclear power with someone and the person just wouldn’t have it. It went something like this:
Joe: Nuclear is bad, it’s dangerous.
Tsk: Why is it dangerous?
Joe: It’s so bad when accidents happens, you destroy massive areas!
Tsk: It can be bad, but nuclear has the least deaths and injury in the energy sector
Joe: Chernobyl was a disaster.
Tsk: Yes, but it’s not representative of the nuclear industry, or a modern reactor.
Joe: And what about Fukushima?
Tsk: One person died in Fukushima, coal plants are responsible for thousands of deaths yearly in comparison.
Tsk: Many Norwegian Journalists decided to come home from Japan cause they were afraid of the Radiation from the reactor, the only problem was that background radiation in Norway was still higher than where they were.
Joe: But it’s not safe, it’s too risky if it goes bad.
Tsk: Did you know 6 grams of uranium-235 is equivalent to 1 tonne of coal in energy?
Tsk: * starts talking about fusion *
Joe: *loses interest, opens snapchat on his phone *
I failed to change his mind on the subject, but I have been successful with others on this particular topic.