Any shoulder or lung to shoulder shot is ethical. I've never tried to shoot anything in the head or neck. I personally don't like those kinds of shots. If I can, I try to take out both shoulders and that will drop the animal in it's tracks (rifle or muzzleloader), If that doesn't work, take both longs and into the opposite shoulder(typically this shot is preferred with bow). This will achieve the same result, in most situations. The animal may still run from a shot like this, but if it's a good one it won't go very far at all. Of course the heart shot is always ethical too as it supplies the rest of the body and without it there is no life
You'll have a very good looking specimen to mount as well as ethical/quick kill.