I found an article titled “Stupid Gun Mistakes EVERY Writer Makes” that has a good list of common mistakes when writing about firearm behavior.  Here are a few, but check out his full list.

THE “EMPTY” AUTOMATIC We’ve all seen the scene where on adversary has the drop on another at the end of a gunfight. One guy holds out an automatic to the other guy’s head, says a take away line (“This is where the rubber meets the road, scumbag.) and then…click. The gun’s empty! Well, when an automatic has fired its last cartridge the slide atop the action locks back. They would both know the gun was empty. At the same time the firing mechanism locks back as well so no “click”. If you need to have a scene like this make sure your character’s armed with a revolver.

That one I knew, but think I’ve made myself. In the heat of writing you want the world to support your dramatic need. Doesn’t always work that way for some strange reason.

THE SUPER ACCURATE SNIPER SCOPE This one’s common. I do it myself but only because most audiences don’t understand how bullets track….

A good point here, in that sometimes you write what the audience needs to see, not what you know to be true. As a bit of a computer nerd, I groan and roll my eyes at some of the stupid things computers (or the people using them) do in movies and stories. But most people don’t understand how they really work, or it would be too obscure to show on the screen, so you cheat.

Overall I knew most of the list, and I’m sure at least one other author on this blog knew them all (and will probably add a few more of his own)…