As stated- I would certainly agree if I hunted those large dangerous animals I’d certainly want something larger than a 58.
I dunno, Sir Samuel Baker felt that the .577 (.58) was the equal of any creature in creation (and he wasn't talking about the nitro version, it hadn't been introduced yet when he said that). Of course the .577 cartridge he was talking about was the 3", which shot a 600gr bullet with 165gr of powder to around 1650fps lol. That being said, when he hunted with a belted ball (essentially a groove-sized ball that had been run through a bore sized swage), he frequently used a 10 bore rifle for anything bigger than deer. On the other hand, he had a good friend that hinted everything in Africa with a cheap 12 bore smooth double the guy picked up in Cairo for a song, with a ball load like a paradox gun would be in the future (3 drams, as I recall), and didn't have too many issues. Sir Baker was also highly impressed with the small bore rifles the Americans were using (breechloaders by that point) to bring down buffalo (which are the same size as CB), elk, and big bear. He was also impressed by J Purdey and Sons's small bore express rifles (both in muzzleloading and breech loading), considered them excellent walking rifles ideally suited for Fallow Deer, Red Deer, and the like.
On the flip side, you have good ol' James Forsyth claiming that anything less than 16 bore (.65) is inadequate for deer... lol. Then again, he also claimed his friend shot a buff in the face with an 8 bore and it had no appreciable effect lol.
animal not immediately going down isn't really an issue, so long as it can be easily recovered and/or changes its temperment. Things shot through the lungs dont live long. It's the matter of driving the bullet through the animal when you get up to buffalo, elephant, and hippo that causes issues with non-jacketed bullets.
Lovin this thread though, crazy how its ran this long lol