You also MUST use steel shot or an equivilent non-toxic shot such as hevishot or tungsten. These may be hard to find and/or expensive in gauges such as the .410, or 28.In 20, 16, 12, 10 they are quite common. Shot size is another consideration. I would reccommend in steel nothing smaller than#5 nothing larger than #2.

Good luck and make sure to ask more questions if you have them. We alllike to help.