You might have a look thru back Handloader magazines for an article by Steve Garbe on the "Return of the .40-60 Maynard." He used .30-40 cases as the basis of this rejuvenated BP round. Can't remember if he had smokeless powder handloads too, but I believe he did. This might be a great medium ctg. that would fit the Krag action a little more easily than the .405 or .40-70. You can make great midrange loads with .41 Mag bullets like I do for my .40-50SS.

If you can't find that article, PM me and I'll dig it up and snail mail you a copy.