Mike as to your question " How Far Away Should I Take The Shot?"
Depends on the situation you find yourself in. Not only do you have to factor in your shooting ability but all facts involved. How you feel that day, the threat level facing you and the one being held, (being shot by you can or could be a less stressful happenstance than letting the threat continue) your own mindset. A situation as this is not only can you make a good shot but does it need to be made. If the answer to the question is YES it needs to be made, does it need to be made even if it's not a 100% success on hit.
I see being faced with this situation being can you live with what ever happens (shoot, don't shoot, victim lives/dies (by you or BG). Is your mindset strong enough to handle it.
Use FMJ, that way if you hit the victim you'll still get the bad guy. Problem solved. :smile: