Well, speculation aside --- I got invited on a buffalo "hunt" some years ago. There were four hunters in the field armed with an assortment of firearms: Two T/C "Hawkens, both .50's, one Resley percussion .38 caliber, and mine. The rifle I had was a .50 caliber Leman percussion so that's what I used. My load was a .495" cast round ball with a ticking patch lubed with YCA #103 ahead of 90 grains of 3Fg Dupont black powder by volume with some pre-patched and pre-lubed .490" RB's in a loading block for reloads that were never needed.
The bull I took was running on an angle away, traveling from left to right across my front at about 35-40 yards after another buckskinner `way off to my left burned him across the withers with a TC mini-ball. My shot took him behind the right shoulder and he went down in the next two strides and stayed down. My hunting partner walked up and - after asking me - popped him behind the ear with the Resley while I was reloading because the bull was still breathing ragged and blowing blood out his nose. When we butchered him out, we found that my shot had gone through the chest cavity and lungs, clipped a major artery, hit a bone on the left and diverted to exit his left shoulder near the base of his neck muscle. On it's way out, it left an exit wound about the size of a quarter. We never did find any part of the round ball.
I haven't hunted buffalo since then, but if I did that same rifle would probably be just fine. If chose something different it would probably be another .50, or maybe a .54.
The bull I took was running on an angle away, traveling from left to right across my front at about 35-40 yards after another buckskinner `way off to my left burned him across the withers with a TC mini-ball. My shot took him behind the right shoulder and he went down in the next two strides and stayed down. My hunting partner walked up and - after asking me - popped him behind the ear with the Resley while I was reloading because the bull was still breathing ragged and blowing blood out his nose. When we butchered him out, we found that my shot had gone through the chest cavity and lungs, clipped a major artery, hit a bone on the left and diverted to exit his left shoulder near the base of his neck muscle. On it's way out, it left an exit wound about the size of a quarter. We never did find any part of the round ball.
I haven't hunted buffalo since then, but if I did that same rifle would probably be just fine. If chose something different it would probably be another .50, or maybe a .54.