There are two main ways to produce leadshot. Both are based on casting. Liquid lead droplet will get a round form if you drop it from 50 meter high. Building a tower and dropping the lead is the very first way to produce leadshot. If we talk about producing leadshot with "machine" this is the Bleimeister technique. Here the same affect is created only in a small height with the help of molding and playing with other parameters.
The material content of the lad used in production is very important. There is not a standart material composition but as general we can say high antimony and arsenic, and low tin level is better for the production. Just for prodution of size over 2,75mm with the machine the higher antimony level is not prefered.
Plating with a graphite powder of leadshot is very important to avoid rust. So a coating drum will help you to do it. This plating helps both protecting the leadshot and giving a shiny affect.