Okay, just picked up my first shotgun. Remington 870 Express Super Magnum, in RealTree Camo. Came with 3 chokes, mod, full and extra full. I later read that all 870 model barrels are interchangeable except on the Express Super Magnum. I was hoping to hunt deer with sabot slugs, but I thought you could not shoot slugs out of a smooth barrel? If I get a rifled choke can I shoot slugs? Or can you buy rifled slugs?