Were it mine, I'd chamber it in .218 Mashburn Bee. Nice sharp shoulder, more than enough velocity for 250 yard varminting, easy to find parent brass. If I needed more oomph than that, I'd do a .219 Improved Zipper. Same excellent features (use either .30-30 or .25-35 brass), an additional 100-125 yards of effective range. Both would have been appropriate in the 1930s.