Back in the 70's my college roommate and I used to use some plastic cases and bullets made by Speer. They took a standard primer as the propulsion. The were decently accurate across the living room, but I would not do that today. I think a variety of things in primers are not particularly healthy to breath. In a normal round that stuff is probably consumed by the charge and you are usually either outdoors or at an indoor range with air flow away from you.