There are some great ammo for 45-70. Buffalo Bore and Garrett
45-70 Magnum - Lever Gun Rifle Ammunition
45-70 Magnum - Lever Gun Ammo - 430 gr. L.B.T.-L.F.N.(1,925fps/M.E.3,537 ft.lbs.) - 20 Round Box
I'm thinking this will do ANYTHING a 458 can do.
This was made for the Marlin 1895 and works in it. I've had no problems.