Mmmmm - i like your thinking....
....possibly...
BUT: what a 'weird' unit to begin from anyway. It just seems so 'arbitrary'.
Can anyone prove to me whether .22 as a rimfire (be it short, long, CB, etc) predates .22 as a unit for air rifle? Should be easy - shouldn't it?
Odd isn't it - that in early 'British' air rifles the No.1 (.177) load is prevalent over .22 - yet in the US it seems to be the reverse.