[spjwebster]

Yours is definitely the spud gun I remember, and I suspect that's true for most folks of a particular age from the UK: a small die cast red gun and a monster potato to feed it ammunition.

If we're talking home made back garden arsenal, the go-to for my generation was the peg gun: https://www.instructables.com/A-Great-Peg-Gun/, which is, in retrospect, absolutely irresponsibly lethal with the right tension elastic bands.