If the elk is in the open away from timber I will shoot for the lungs. In the timber,or on the edge of a "hell hole" shoulder shot. I usually hunt alone and the last thing I need is a rodeo or long tracking job to some nasty ravine with a bull packed into it.
I hadn't had one of those rodeos for years until this year when I shoulder shot one with too soft a bullet. But that's another story. BTW I don't like shoulder meat that much anyway.

Lefty C