I have a sporterized Lee Enfield No.1 Mk III. I am unsure of what actual caliber it is since it was bought for $20 at a garage sale about 15 years ago. It is missing the safety, but I can order them through Springfield Sporters pretty cheap.
I was just at a gunshop and saw a Lee Enfield conversion in .45-70. The barrel was stamped Navy Arms (?). The bolt looked like it had little modification and a new flat magazine follower.
This started me thinking in maybe doing a redo with the old sporter tucked in the corner. Maybe in a "common" caliber that is easy to find boxer brass for.