I've got a couple to add to the list. Had a gun store employee tell me that the reason cops use Federal Hydra-shock ammo was that the little lead post in the bottom of the hollow point made it proof-positive against body armor. It did something to the bullet that guaranteed penetration through all types of armor and trauma plates. I responded that I had assumed that it had something to do with initiating expansion. I was informed that that was ridiculous, and that he had access to better info as a gun store employee than I did as a civilian.
Was in the LGS looking at concealed carry pieces. The helpful employee there assured me that in Virginia, if you have a concealed-carry permit and you should happen to encounter two unarmed people in a fist-fight, you are legally permitted to shoot the aggressor! I looked at him with an obviously stunned expression on my face, then he claims that is exactly what the guy who gave his CCL class said, and that he had even looked it up in Virginia State Code.
Folks, I assure you, while Virginia is gun-friendly, no such thing is even remotely true! I honestly wonder how some people remember to keep breathing.
In an unrelated matter, I was once in the local Walmart at the ammo counter. There was a woman in line just ahead of me that wanted some .410 shells. The counter guy, who happens to be the FFL holder for that store, turns around and grabs a couple different boxes and lays them out on the counter in front of her. He points and says "this one is bird shot, this is #4, this is buckshot, (etc.) What are you shooting at?"
The woman picks up a box and says "I'm going home and shooting my neighbor's dog. I'm sick of it piddling all over my bushes."
The counter guy leaned over the counter and snatched the box out of her hand and says "I'm not selling you anything." He looks at me and says "What can I get you, sir?" The woman stands there for a minute, fuming, stamps her foot and leaves. I sometimes wonder if that dog is still with us.