Pattern the thing at 40 yards at a 30" circle, you'll be surprised what I/C does. Shoot several loads, different brands and see WTF. Different weights, 1oz. vs. 1 1/4oz etc, will show you different results.
Guys would be blown away if they actually "sighted in" their shotguns. I know my Citori is 60/40 70% with .727 choke and 7/8oz 7.5's.
