In the movies Howard Hill used to shoot a wooden block on the back of a "cavalryman" as he rode by. I don't know who had more guts; only that I wouldn't want to be the shooter or the shootee! IMO, if the shooter and the shootee are both OK with it, go ahead. They're both nuts and if one of them gets shot out of the gene pool, is that a bad thing? Seriously, they both know the risks, they both know the consequences and if they can "live" with the consequences, it is (still, barely) a free country. I know common sense isn't common, but hopefully most people will be smart enough to not try this at home.