Honestly, you can't. If you were to take one apart, you still wouldn't know the type of powder used. Then you would need the exact wad, and buffer. Then you would need the exact case. Buy the newest Lyman shot shell manual, and look for a combo that is similar, is the best you can do. Shot shells are not like loading center fire rifle, as you have to follow the exact load data, or you can get in trouble quick.