If I were doin' this (of course I'm not....), I'd do a .25-35. More bullet choice and more versatile: you can load it to replicate factory .25-20 up to near a .250-3000 in a strong action like that. No case forming.
Lighter, better shaped bullets with a little more "ooomph" that a strong action allows takes the .25-35 into big game territory. And you can call it a "6.35x52R" if you're feelin' all "Continental"!
