I just received a couple of ER Shaw rifled 12GA shotgun barrel blanks. I have a Greener GP 12GA shotgun action and I just sent it off to a gunsmith for barreling with one of them. This gunsmith has extensive double rifled shotgun building experience so this should be a cakewalk for him. He usually chambers all his 12GA guns for 3 inch shells, even though it's a little difficult for 3" shells to "turn the corner" on the Greener action. I'll probably shoot 2-3/4" sabot slugs in it, but I saw the thread about round balls and brass cases. I wonder about loading for this gun. I'm kinda surprised that no one else has done this before. Maybe they have and I haven't noticed. Anyway I'd like to hear any suggestions about getting this gun running right. Thanks in advance. Allan