I know a guy who has been shot and survived in spite of the horrendous scars he has where the bullet actually deflected off bone and exited then re-entered his chest. The bullet bounced all around his chest and stomach missing his vitals. He didn't just lay down and wait to bleed out.

I couldn't care less how anyone else sights in but I hope folks will at least look at the info presented in the links and try it for themselves.

As for hostages and head shots, I've only tried it on cardboard while watching others do the same. It can be quite humbling when a shot slips into the white...

BTW, which red dot are you running on your HD AR?