I think its time for some stickies in the black and green shotgun forum! You can fire foster, AKA rifled slugs through any choke, though full is usually recomended as a limit. The rifling allows the slug to compress as it passes through the choke constriction, and the hollow cavity in the rear makes it nose heavy so that it will fly straight like a badminton birdy. Sabot slugs require a fully rifle barrel or rifled choke tube to spin stabalize the rear-heavy rifle bullet, so that it doesnt tumble.