I disagree. I think, that in the hands of good shooter, it would be adequate. I have never shot a Buffalo with one but I have shot a couple with a .303 and .308. I have shot an Alaskan Moose with my 1903 with no problems. The penitration with the long bullet is outstanding and should be fine.

As with all smaller calibers, shot placement is more critical but it is always critical anyway.

There is nothing wrong with hunting with an older caliber.