Bulzeye:

You received a few good suggestions.

Like Bigbulls suggested you can clean them up and shoot them. Just don't tumble them because the motion might break down the powder in size or shape and change the burning rate and cause pressure change.

Like JLmoore1956 suggested you can disassemble the rounds. The powder works well as fertilizer, and the primers will become inert if you soak them in oil. Good luck