Speakin of buff huntin.........here is a quote from "North American Bows, arrows, and quivers" ; Otis Tufton Mason ; first appeared in in the "Annual Report of the Smithsonian Institution" 1893. This quote is Mason citing Oliver Marcy from "Science, vol. VII, p.528"
"I have in my possession the sixth dorsal vertebra of a buffalo, the spine of which contains an iron arrow point. The arrow struck the spine about 2 inches above the center of the spinal canal, and penetrated the bone .82 of an inch. The bone at the point struck is .55 of an inch thick, and the point of the arrow protrudes beyond the bone .27 of an inch. The arrow was shot from the right side of the animal and the plane of the point was horizontal. The animal was mature and the bones well ossified. Though the vertebra has been much weathered, the epiphyses adhere closely. The animal was not as large as some individuals. The whole vertical length of the vertebra is 13 inches.
"The arrow must have penetrated several inches of flesh before striking the bone." Otis Mason adds; "He does not take into consideration also the thick hide and matted wolly hair, both especially thick at the point struck."
This is only one arrow point in one animal, so there isn't enough info to make general statement, however in this case here it appears that the shot was from horse back, and aimed either for the spine or was a lung shot that hit high. Just some more of my "internet crap" research, so take it for what it's worth. For the scientific types the book is considered ..." ....but still remains viable as a study of the subject, and even today few works surpass it." Written by Steve Allely, April 22, 2007
rich