Well if they were up to no good and seen you had weapons,I doubt they will be back.
You did well,
In Georgia, you do have the right to protect yourself and your property if threatened.
Next time ensure that yours is the only story that can be told.
"theres gonna be alot of slow singing and flower bringin, if my burglar alarm starts ringin"
how close is your nearest neighbor?you are responsible for whatever the bullet hits, you should take up bow hunting (...arrows are silent and will even pentrate most vests...I mean, can disable a vehicle if need be)
Personally, I would have put a round through the engine then let them explain themselves to the cops. I know I know some might think that is harsh, but looking at that picture, there is no way they "accidentally" drove in the driveway.