I was thinking .22LR or .17HMR, because I forget that airguns distinct from airsoft exist, haha. BB gun is equally plausible, for people who aren't me! :D

I like your headcanon on what "taking the obvious course" means. I still think that if there's a combination, the end result is still probably a favorable number, even if that means one of them is essentially meaningless, like "betrayal that doesn't actually harm anyone" or something. :D