Depends on what bullet you are shooting and how far off it is.

I have always tried to shoot behind the shoulder regardless of what animal I am shooting at. Unless the angle of the animal dictates taking out one shoulder. I have never purposly attempted to take out both shoulders on any animal. I hate to waste all of that sausage and ground meat by making it into a bloodshot mess from the bullet and shattered bone. I honestly do not see the point of purposly shooting for the shoulders. It doesn't kill them any quicker. So they run 50 yards, big deal. Nine times out of ten if they are woulded through the lungs/ heart they will run down hill any way only making your packing out job just a little bit easier. I could see it if they were close to the edge of a cliff.

Of the five I have taken with my .270 none have had both shoulders broken and only two were at such an angle that I had to take out one sholder. That farthest that one ran was about 75 yards straight down hill.