Years ago, when I was in the Air Force, I had a friendly disagreement with a Staff Sergeant in my shop. We were discussing a scenario where you're at a rest stop by the interstate, way out in the middle of nowhere (people actually have been killed/abducted at these). Anyway, the scenario is that it's broad daylight, you're at the rest stop standing by your car and stretching, and two men approach. One has a knife and one has a tire iron. They're walking quickly toward you and making threats. You are armed and they don't know it (yet). Here's where the disagreement comes in.
Tell them once, "I've got a gun." Don't make the gun visible at all yet. If they don't believe you and keep coming, pull the gun and shoot them.
No way. Pull the gun, get into your stance, and show them that you mean business. Most likely they'll turn and run away.
"No, no. You never pull a gun out and 'wave it around.'"
Now, it seems to me that my response is best. I would much rather have those two run away, then I drive away and it's over, than to be forced to kill at least one of them because they thought I was bluffing. Don't even get me started about future ramifications, paperwork, being stalked by the friends or family of the two men, etc.... Further, I hardly consider it to be "waving a gun around" if they're quickly approaching you with clear intent to injure or kill you.
What do you think?