Charlie lets em get so close you can easy kill them with a 20 gauge, not sure why he does all this long range testing, pellet counts, etc. I'm thinking too much time on his hands......
To be honest, once your done all your technical stuff, the best way to become a great shot, is to find what shell your comfortable with, out of what shotgun, with what choke.....AND THEN DON'T CHANGE ANYTHING!!!!!!!!!!
I know I can kill a goose at 30 yards, with a federal, 3 1/2", ounce and half, BB(1450fps). Shot out of my VersaMax, with factory modified choke. Once you get the recipe, you know it will work. Changing any one of the 3 things, gun, choke, shell(especially different speeds) will of course change everything. Any experience waterfowler will tell you the exact same shell will react differently shot out of different guns, etc.
So once you have your desired gun, choke, shell combination..... if the bird at 30 yards doesn't fall, it ain't the shell, it's the shooter.