Where do .22 and .177 come from? ...and Why?

[El Garro]

I wonder if the odd sizes may have been influenced by rifling in barrels, weren't some early bore sizes measured from the lands and some from the grooves ?
just a thought but may help explain the odd sounding fractions of an inch.

Edit. Doh, just read the other thread and see this has already been mentioned, so thinking on my feet I'll go for my original thought on this that they found out that 200, 250 and 500 of all said sized pellets would fit in the re painted lozenge tins they decided would be handy to keep them in
I'll just get my coat........