Al Thompson
Moderator Emeritus
Thought this was interesting, though I'm not sure why he included both the 50 yard and 200 yard zeros.
http://www.youtube.com/watch?feature=player_embedded&v=8iCNIRuQuBg#!
http://www.youtube.com/watch?feature=player_embedded&v=8iCNIRuQuBg#!