9mm is the SD round that I am most able to afford to shoot 6,000 of per year, so that is what I carry (I also shoot a lot of .22LR and .177, but not out of repeating firearms).
Rust and bureaucrats. Freedom and vigilance. Front sight and trigger. Kindness and firepower. Situational awareness and tolerance. Safety and concealment. Taxes and allegiance. Love of man and surgical marksmanship. Once a soldier, always a soldier.