Using a shotshell reloader, like a MEC reloader for example, shotshell hulls can be filled with your choice of components, from the size of the lead shot to which type of wads and what primer brand is used. A list of shotshell reloading supplies might include Claybuster wads, 209 primers and the appropriate smokeless powder. The large variety of components available means you can tailor your shotshell for your particular shotgun and target, whether it be clay birds or hunting small game.