this is a very interesting subject, and it gets really deep really fast.. the old lead three inch 1 7/8 oz lead shot for example had a lower velocity than the 2 3/4 inch shells.. to get the same pennetration with the slower velocity you would need bigger shot, this thinning the pattern.. steell looses velocity very fast becouse of its low specific gravity, so large shot needs to be used.. this is hellped by a bigger hull to carry larger steel shot, but it still need velocity.. the size of the bird needs to be taken into account, wheather its flying away, toughness or how big of a bird, time of year giving more or less plumage.. once a gun gets past a certain shell size it gets heavier to reduce the effect of recoil.. if the gun is too light, or the load is too heavey some hunters cant hit the broad side of a barn.. all of these things need to be taken into consideration.. if one knows his game, shells, and is a skifull hunter, the 2 3/4 will work very well for him.. pass shooting high flying geese by a person who doesnt mind recoil can work well for that person using a 10 gauge.. the guys i know who get lots of geese usually, not always, dont have big guns, they know lots of places to go, have decoys, and are skillfull hunters and they out do other hunters by determination and skill.. its a very interesting subject.. and everyone has thier own way.. Tom roster published some very intersting data as to the number of pellets and size of pellet for differnt tyhpes and sizes of water foul.. for instance teel need 110 pellets in a 30 inch circle at shooting distance if i remember correctly,, and each bird had its rating for a three pellet hit on that bird thru the pattern.. this was published in the montana waterfouling fish and game annual rules book years ago. i stull use it , pattern board, and phone books (for pennetration tests) to work up shot gun loads for black powder hunting. its effective also for flintlocks with cylinder bore..the range needs to be shortened, the shot needs to be larger becouse of lower velocity, and the number of birds brought home is reduced significantly... ive watched many thousands of ducks fly over while stuffing powder wads and shot down the bore.. and gone home many times without a bird.. but it doesnt bother me a bit.. its all what you want out of your day off.. dave..