Converted mine to a .30-40 Krag about a year ago...bought the reamer and plunged in. I bought a fiinish reamer and actually, if I had thought twice about it I would have bought the .30-40 AI instead of the standard .30-40..the Ackley Improved lets you shoot standard .30-40 rounds or fireform AI rounds.
In the single shot handi rifle (as long as you've got the SB2 receiver, you can load your Krags quite a bit hotter than you can in a Springfield Krag rifle. Be careful. I'll not pass on loads here, but they are out there for the Krag for single shot Ruger, TC contender, and other single rifles chambered for the Krag (these loads specifically tell you do not load for the Springfield Krag)
I did end up having to polish the chamber using FLitz and a case I attached to a threaded rod (with power drill)to get the rounds to eject properly after firing. Works perfectly now, and is a powerful 150-175 yard gun now with 180 and 200 grain bullets usuable.
Took a deer this year with the Handi rifle at 150 yards up hill.