I have only seen three American buffalo taken, one with a .45-90 and a cast bullets weighing close to 600 grains, one with a .375 H&H with handloaded 300-grain Nosler Partitions, and one with a .270 Winchester and a 130-grain Barnes Triple-Shock.

Heart-lung shots were used on all three. Only the bison taken with the .270 was killed with one shot, and it also went down quicker than the other two.

“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck