I-too often think of the other greats, often spoken of as adequate for the hunter. I am referring to the .375 H&H and the 450/400.
: Realistically, the .45/70 is capable, if loaded to match either of these rounds, in tissue damage and penetration.
: This is why i said it was definitely adequate. Would I chose it, no, but if the 450/400 is adequate, then so is the .45/70, if laoded to the same power levels with bullets that will penetrate.
: Is it adequate with 400 gr. Speers, NO. That wasn't the original question.
: Is the heavy lead bullet loafing along at 1,600fps adequate, I don't honestly know. I know that Elmer Keith said I would have no trouble with that same weight hardened bullet at 1,900fps to 2,000fps from my bolt .458 2".
: I suspect it would work OK at the reduced velocity, but be aware, lower 'power' due to less velocity in that amount is a noticable result, and killing is generally slower, but do the job, it will. Some areas might not allow this necessary 'time' factor, though, due to presence of preditors.