I don't have any experience in Africa but I have hunted Sharps rifles exclusively for the last five years here in Texas. Here are a few observations.

1) Any of the Sharps cartridges 45-70, 40-70ss, etc when loaded with black powder and lead bullets are going to be marginal hunting loads. Any way you slice it, a soft lead slug at 1120fps to 1350fps is "low and slow" and about on par with a hot loaded 44 magnum. I consider my 4 3/4" 454 Casull to be a much better game killer up to 75yds or so.

2) When loaded to maximum with smokeless the 45-70 could be a decent plains game killer out to 125yds-150yds. With the 400gr jacketed bullet. After that, the trajectory gets to be too much for accurate field shooting. The 40-70ss with smokeless can get a 300gr jacketed bullet up to around 2000fps. You might be able to reliably stretch that range to 200yds if your eyesight is good.

3) Any of the Sharps cartridges seem pretty much under powered for dangerous game. The 45-70 is stuck with stubby 400gr bullets to get into reliable jacket opening velocity range. Pumpkin roller comes to mind. With the 40's the situation is a bit better for sectional density but the foot pounds on target is still pretty marginal.

4) In my opinion, with smokeless and good jacketed bullets the Sharps rounds would be fine for plains game at reasonable ranges. When it comes to dangerous game I would consider the Sharps rounds to be in the realm of a stunt. Just not enough power.

5) Lead bullets and black powder would be more closely likened to muzzleloader hunting in Africa due to the lack of velocity.

That's how I read the deal.

Sharps
Josh