Some have suggested that high velocity rounds anchor them.
Also some seem to think overkill anchors them.
I've yet to find a round that drops them in their tracks more so than another, although not only are we comparing rounds to other rounds, but don't forget different bullet types within a given round.
So many options, and I too am not sure if it matters, I've yet to come to a conclusion.
I've seen a mulie dropped in it's tracks with a .25-06, and I've seen a BIG black bear go about 3 steps with a .300 win.mag., everything else I can think of has ran some distance even though they were dead with 1 shot...
I have heard/read that the .257wby has an uncanny record of dropping game in it's tracks...