With smokeless (or BP) loads, the .50/70 can be a great round, however for much more power, the .50-110 or .50/90 Sharps are two other suggestions. In the #1, the .50/70 should quite easily make over 2,000fps with 450gr. bullets - should let you know you've fired something powerful. The reason I suggest those ballistics, is that it has the same capacity as a .45/70, but with greater expansion ratio = higher speed with same weight at same pressure.

While the .45/70 #3 has a very thin barrel, the #1 might be able to be re-bored, but usually it's just as cheap to re-barrel. You would also probably end up with a better quality barrel. So - new barrel, chamber and maybe new extractor - quite simple. I expect the .45/70 extractor could be modified to work just fine. A quick check in Richard Lee's new book , shows a .45/70 running 2,100fps with jacketed 400's at 47,000psi. The .50/70 should make about 50fps to 100fps over that with the same weight bullet.

With a pressure limit of whatever the brass you use can handle, it is a VERY powerful round.

In retrospect, I'd simply chamber it for the .50 Alaskan, which is a blown out .348 Winchester case - ie: 2.1" long. It is a VERY power full round and one I have some experience with, but in less strong actions.

Cases are easily found and made.

This brass is EVERY strong and will allow you to load to the capability of the rifle's action and barrel - which would allow ANY and ALL African dangerous game shooting.