This particular co-worker and I have many conversations about politics, religion, guns, company policy, military etc.
I'm glad you can have that kind of conversation with coworkers. It's not frequent where I work and I see it passing from the American scene.
I cannot think of one other subject where people with a little knowledge try to out-expert each other.
I think this is the reason why - and that was the point of my first post in the thread. IIRC the OP's point is the wrong stuff we hear about guns, and in my case I had someone who wasn't knowledgeable at all about guns explaining the intricacies of offensive and defensive ammo statutes - which don't even exist in law locally. At all.
He's knowledgeable on other subjects and we see eye to eye on a lot of other stuff, so I just let it pass over without getting into it. It would require requalifying my credibility which he's already aware of. I don't need to prop up my ego and be The Man Who Knows All About Guns at my workplace (and I'm not saying the OP does that, either.)
But it does go to a constant social jockeying in conversation where one person attempts to place themselves as the "better" guy and who can tell everyone else what is what. I generally find that the more they push that concept the more they are a blowhard who lack substantive knowledge or experience.
It's attributed to Mark Twain - don't argue with stupid people, they will drag you down to their level and beat you with experience. As time goes on I'm less inclined to even listen to them, or insert my opinion in a conversation as it ruffles their feathers. They get defensive because they see that input as putting them in their place. That's where the problem lies - somebody DOES know more about it than any one of us do, so what we should be doing is listening to them.
For the most part now, tho, we get to listen to some really uninformed and even dangerous ideas which are usually presented for their social impact, not their factual basis.