Check out this link. It has tons of info on terminal ballistics. About half way down the page is a link to a study done by the South Carolina DNR. They shot several hundred deer and logged the results. Very interesting I thought.

http://www.rathcoombe.net/sci-tech/ballistics/mechanics.html

I believe shot placement does make a difference. If you aim for a high shoulder hit you are more likely to drop the deer on the spot because you have immobilized it. That doesn't really mean it died that quickly though.

I haven't had very good luck with lung and heart shots with a muzzle loader and slug gun inside of 100 yards. I mean it kills them for sure, but they run, often times 50-100 yards. I might try a high shoulder shot next year just to see what happens.

I have never hunted with high powered rifle, I have seen lots of footage of it though. And it seems rather unpredictible like the study shows. I will see one hunt were the deer doesn't drop with a fairly powefull rifle. Then another with some kid using a 243 and the deer drops like a sack of bricks.

Paul