There are a number of great companies that produce dummy rounds for training. One of the best is the Fake Bullets company. They offer a number of features that are worth drawing attention to. First that offer three case materials, black, brass, and nickel.
I recommend using brass cases if you will be making direct contact with the rounds while reloading, i.e. reloading loose rounds, or drawing from a loop ammo carrier or a 2x2x2 pouch.
