There was a company a few decades ago that produced a similar product. I don't recall them having shotgun rounds, but they did make reloadable handgun rounds. I still have a souvenir key ring 38 special round they made. It consisted of a plastic and copper shell caseing, a copper plated "snap-in" bullet, and it was powered by a primer only (no powder). I think is was marketed for indoor practice/plinking. This was before the days of airsoft. If you are interested I will try and find it and post a picture.