I think single shots and rimmed cartridges are made for eachother, and that being said I'd like to see a handi in 405 Winchester, and 9.3 x 74R, and maybe even one in 50-110 in a bull barrel.
I have often said the same thing conserning rimmed cases/cartridges. Its not founded in extraction problems with rimmless calibers in ejector handis. There is just something that seems "right" about older, rimmed calibers in single shots. (oops, I said it again.

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its not been mentioned for a page in a half.. A 25/35 would be great. Even better in a long tappered octagon barrel with a good set of buckhorn or ladder open sites!!
CW