My 45-70 is very accurate. Several different loads have fired into an inch or less at 100 yards. Once I fired a 100 yard 3 shot group of 350 grain RN Hornadys that I could cover with a nickle, that is not center to center, that was edge to edge. Groups with 4-5 shots grow to an inch however.
I might add that the 45-70 always seemed to me to be the single best loading for the Handi. Not just accuracy wise, but what you got for the money. When I bought it, the next most affordable 45-70 was a Marlin lever, then the Ruger #1, than the Browning 1885. My handi is at least as accurate as those. Plus, when you consider all of the problems some have had with rimless rounds and ejection, rimmed cartridges always seemed to be the better choice. My 45-70 will spit an empty case out vigorously. You have to be careful while shooting at the bench not to eject a case into your face!
I will keep mine forever. Nuf said.