Well when we have so called "leaders" saying things like a 9mm will blow the lung out of a body is it any wonder why so many people think this.
These people are so ingrained in trusting what the TV tells them that when you say.....ahhh no. It will really upset the apple cart. When they try to move to "show the victims" Well we can go that way in a minute if you wish, lets talk about the original topic first.
When backed into a corner they try to straw man the argument, they can't defend it with logic. The key is to go slow, listen very carefully to what they say, ask a question about their question, or restate their question to them to make sure you "understand" their point. Then start with the facts and sources to back that up.