I'm on your side in this Hornet. Since this has happened to you before at that 7-11 with the brothers giving you grief about the cowboy hat and all...I'm thinking the best self defense in the future would be to not go to that 7-11. I know it sounds wussy to avoid a place where trouble might happen, but if you had used the gun and killed the thugs, having had trouble there before, it might look like you went there with a gun with the intention to shoot someone. At least that's what a prosecuting attorney might say. That you had the gun because you were expecting trouble, i.e. looking for it.
Another thing, what if the thugs hadn't backed off at the sight of the gun? Then you'd have to shoot them. You would have gotten in trouble, unfortunately.
I'm not saying what I would have done under the circumstances. No one knows what they will do until they do it. It would make sense to roll up the windows and get out of there soon as possible. If I had to say anything it may have been something like, "No thanks, not today." If I had problems at that 7-11 before under similar circumstances, I wouldn't have been there to begin with.
Glad everything turned out well. Using the word "you" in a global sense, it's a rough situation where you have to wait for someone to attack you first before acting. I've always heard if you shoot someone, to tell the Police you were in fear for your life (which wouldn't be a lie.) Please don't take this as a personal criticism. It's not. In my uneducated opinion, if you had killed one of those thugs, the biggest obstacle to a self defense argument would be that you went back to that 7-11 when you had this happen in the past and knew it was likely to happen again.
Les