I respect Bob Brister's "Shotgunning the art and the Science" when it comes to patterning. His chapter on "How good is your duck load?" should answer a lot of statements on this thread. It particularly points to the results of the Nilo test by Winchester in which they shot 2400 live mallards at specific distances with a soope sighted shotgun. If a load can't kill a duck consistently that way--without leading even being required, it is not a good enough load for real world shooting with all the variables which often place the duck in the fringe of the pattern. The results are sobering for sky blasters...