As Slim already stated, it not safe to switch componants in shotgun loads. If you do not want to buy a Shotgun Reloading manuls all of the powder manufactures give away small manuals that are up dated every year and you can get the latest and most reliable data from them, just ask someone where you buy your componants. I would highly recomcnd you buy the Layman Shot shell reloading manual , it has alot of very interesting charts and tables on exteror balistics where you can learn alot about what size shot will do you the best job for your shooting.