Several points I'd like to comment on.
Wet newspaper, as was mentioned, has been used an a ballistics test medium for many years. I don't believe Garrett was trying to pull the wool over anyones eyes, it's simply whats available and generally accepted, tho I still do not believe it is an accurate predictor of what bullets do in animals, especially heavy African animals. Hands on experience trumps the theoretical testing every time, particularly when that hands on experience is over long periods of time and a large number of animals. We don't have this in regards to a direct comparison of the 458 and 45-70 with the rounds loaded today, but we do have many years of use of the heavy British rounds and the 458. In case anyone missed it, the 458 Winchester isn't a newfangled whiz bang fresh on the market, it came out in 1956, it wasnt something that was dreamed up by an advertiser to dupe unsuspecting sportsmen. It was trying to duplicate the performance and ballistics of British rounds like the 470 Nitro express (which came out in 1907), a 500 gr RN bullet at about 2100 fps, but in a magazine rifle (bolt action). The bullet shape also wasn't just a wild guess that they stuck with because nobody was paying attention, it was what worked, after experimentation and long use. Read Taylors book, he discuses this in various cartridges. Round nose bullets of the proper shape penetrate extremely well, poor shaped round noses and poor materials do not penetrate as well and change directions in large tough game animals.
A flat point sharp edged bullet penetrating more than a round nose, all esle being equal, does not make sense. I do not believe this is a factor. A flat nose and sharp edged bullet disrupts more tissue and causes more damage than a round nose bullet. Disect wounds made with both types and compare, it's obvious when you do ow much tissue damage there is with a flat point sharp edged bulet comapred to a round nose. The result wouldn't be more penetraion, it would be less, similar to a soft point bullet compared to a solid. If the flat point was truly cutting a wad of tissue, it would have to push all that ahead of it, which I do not believe they do. They do cut tissue, but it still has to part the tissue to penetrate. Soft points, all else being equal, don't penetrate as much as a solid. The energy used for tissue disruption and bullet deformation is energy that isnt being used for penetration. This is the simple facts, and why solids exist for dangerous African animals. We can have some of both in flat point bullets that we use on large animals in the States, but we arent shooting elephants or breaking down Rhinos or Cape Buffalo. In case anyone missed it before, American Bison aren't the same animal as a Cape Buffalo. Whatever the 45-70 or similar rounds did to kill American Bison in the past, it really has little bearing on this discussion. Nobody is disputing the past and what was done with them, the discusion is about comparing the modern loadings of the 45-70 with the 458 Winchester and 458 Lott. The Lott was developed by guys that shoot elephants, not internet or even American game hunters. I don't believe it would have got off the ground if it didnt work or penetrated less than the 458 Winchester round. again, experience and hands on trumps theory and wet paper. It exists because it filled a need, and functioned.
I think the best evidence of the penetrative abilties of the modern 45-70 loads is to give guns and ammo to some African guides to use for a couple years to compare to the standards they use now (or give them ammo loaded to modern 45-70 levels to use in their 458's and 458 Lotts) and see how they feel about after shooting numbers of animals. I don't for a minute dispute what the round has done on Cape Buffalo, just the contention that it's better than other rounds already in use, especially on elephant. The years (over 100) of use and literally tens of thousands, if not hundreds of thosuands of elephants killed with the 470 NE and similar rounds, and the 458 indicate they work rather well. Read some first hand accounts of those that did Ivory hunting, guiding, or culling. If the round didnt work very well, they didnt survive. Standing 30 feet or less from angry animals of that size and being able to reliably break them down or make reliably killing head shots is of paramount importance. There's no second chance for the most part, if the round fails to perform, you die, period. Lott and some others wanted a little more, and they got what they wanted, but the older rounds still work rather well.
I'd be interested in knowing more details of the tests on dead elephants shot with the heavy 45-70 rounds. The results don't surprise me, tho having more details would add much to the discusion. As it stands, without specifics it's interesting, but doesnt have as much weight as having specific information about who, what, where, when etc.
I think the 45-70 is a very interesting round, and quite up to anything I'm going to do with it for my neighborhood (grizzly country) or even Alaska, but I don't believe it's equal to the 470 NE, 458 Winchester or 458 Lott for African use. Yes, it will kill much African game, and pretty well, nobody is disputing that, that I've been able to tell, tho I'm not sure I'd want to be backed up with one if I was doing the shooting. The physics and math are interesting, but long use and experience indiate the common African rounds do the job. If they didnt, they wouldn't continue to be used. everyone has been tlaking about a single, or few instances of Cape Buffalo being killed, and killing another one behind it as the validating point fo the Garrett/modern 45-70 loads. Ok, good, thats a good starting point, but that's nowhere near the level of experience we have with the accepted loads used there. Lets get some hands on experience with more game, and a bunch of elephants (maybe 100 for a sample) before we all go shouting about how much better it is. That would be the defining moment, not wet paper and a handful of Cape Buff.