Here are some pic's of Beartooths Pile Driver 525 gr cast bullets recovered from the carcass of a hippo bull during my hunting season in 2011 fired from my 45-70 1895 GBL with 18.5 inch barrel.
Load details are: Winchester brass & Win. LR magnum primers, loaded with 40gr of H322 - check the beartooth website for more accurate details on load data - HERE!
The bullets were test fired into the hippo carcass once we had recovered it from the river and after my client had shot it so it was not alive but we had not started the skinning yet. Unfortunately these were the only bullets I had time to recover - I had to quarter the hippo and hang it up as Lion bait asap - so likely there a few lions and Hyena's with lead in their belly.
These BTB shots were aimed at the middle of the shoulder from 20 feet and broke through both the heavy shoulder blade and the ribcage (without fracturing bone, clean holes), traveled through the vitals to the opposing ribs. One bullet travelled through the opposing shoulderblade and lodged under the heavy skin while the other was firmly stuck in the shoulderblade.
There were 3 other PH's in camp with me - I went to Africa with two 45-70's - one 1895 GBL out of the box and another customised by Wild West guns out of Alaska - needless to say that I returned home empty handed, so impressed were they with these small dynamite sticks! The concensus in camp was that it would not be a first choice stopper after wounded buffalo or elephant BUT we all would have no hesitation taking it in after wounded Lion or Leopard with quality soft points.
Many older supposedly "more experienced" PH's have called me a liar to my face when I mention this but I grew up in a country where rifles were scarce and you took what you were given - in my case a .300 win mag. when I turned 12 years of age. From that time until I was ready to start hunting professionally, I shot close on 40 buffalo - all of them with my .300 win mag shooting 180 gr factory ammo. (that's all we could get) - I never had a full charge from any and most of them were dead from the first shot although it didn't stop me putting in as many as I could.
I always bear this in mind when we talk of the killing power or ability of the 45-70 and in my case the 18 inch guide gun - this "little rifle" is phenomenal - with modern powders, all the variety of bullets available and info from sites like this one, we can take on anything that walks this earth without having to worry about the much hyped 'use enough gun' theory.
Personally I like the heavy grain bullets in the 45-70 because I grew up always wanting something a little more than my 180gr bullets from the .300 (just being a kid!) However a 350gr bullet from the 45-70 at reasonable speed, placed where it should, will do the job on most if not all of Africa's big game.
The 45-70 doesn't need to live up to any of the big bore calibers - it is a law unto itself.