well yea im shooting steel im shooting ducks... duhh

Well there's other stuff like bismuth and Hevi Shot etc.. I was always told that full is too constricting for steel.

Pygmy, i agree with you the choke tube controls the pattern. But the pattern starts to open up whenthe shotleaves the barrel. so the gun with the longer barrel makes the shotstay together longer, 10 inches longer in our scenerio. Which would result in a difference in pattern. Try it, the shot from a shorter barrel will be a little more open than the longer

the backboreof a barrel has as much to do with the size of the shot pattern as the choke. most 21in barrel guns have a larger back bore so that they shoot the same size pattern as a 30in they are shorter in length to make them easier to manouver around in the brush that is why most bird hunters shoot spreeder wads to get a bigger pattern the size of the pattern might be 1/2in bigger from a shorter barrel but not enough to make a noticable difference. most short barreled turkey guns will shoot tighter than 30 in barrel gun because of there back bore.

riverboss, ill buy all that.

I shoot mod. for Ducks normally and Full or X Full for geese just depending on what time of year. If you are gonna shoot full or X full you best be able to shoot atleast a 23 in skeet!

i still love shootin my full choke no matter wat anybody says

I love my patternmaster! Also am getting a Kicks choke soon!

BUY A PATTERNMASTER! my buddies and i jus bought them this year and it is amzingmy hunting grouponly lost 2 ducks all season (and we hunt pretty hard) trust me you will be happy you did. i dont know bout u but i love to pheasant hunt and man do we pillowcase them birds. they are worth the money if you like to hunt.

sounds like a good theory but still not totally true. like you said IF the barrel is backbored. look at remington, the barrels are not backbored and the 21" turkey guns are the same ID as the 28" duck guns.
another factor is your speed. while modern powders are fast burning compared to many years ago there is still a bit of velocity difference between a short barrel and a long barrel gun. the velocity will effect your pattern esp when you reach that super/subsonic breaking point.
while we are at it why not through in humidity and elevation???my gun shot in new orleans will shoot tighter then yours in montana.