ok everyone there is so much talk about aftermarket chokes....Im just starting to get big into goose hunting and need to know the basics on shot size's and chokes.im shooting an I-12.what does everyone recommend shooting for shells,oz??bb??t??...and what factory choke should i shoot.im shooting over decoys in wheat stubble,my decoys are all shells(not any fancy full flocked full bodys) so the geese never lock in hard and want land, a lot of high shooting goes on.give me some incite and knowledge please.thanks