The .30-40 is pretty easy to load. I found 180 Nosler Ballistic tips and 4350 worked well with my original Krag:
It didn't do as well with shorter bullets. That is a 100 yard group, with the rifle as you see it, a receiver sight in place.
I may try to knock off a deer with the Krag this fall, then give it to an uncle, as it's an old family gun and he has kids & grandkids who shoot. I would like to have a #1 in either .30-30 or .30-40. In the .30-40 one could take advantage of the action strength - but I won't try it if I still have an old Krag around!