I recall .22/303 (about three versions from full length to shortened), .243/303, 25/303, 270/303 & 7.7 x 54 (thanks 93x64).

Undoubtedly there were others. "Necessity being the mother of invention"...….and the father of halfcastes.

In the colonies, well at least Australia, they were cheap ex military SMLEs when commercial sporters weren't common/cheap. People made the most of what they had.

The action strength was the limiting factor as to performance, with the SMLEs, but I'd say you could make some of these cartridges really "cook" in a P14 or a Mauser.

I'd still have 25/303 dies and cases somewhere though I never had the rifle.

You could go along way with a sporterised .303 and not be found lacking. Bell found that out.