I aquired a box of various cartridges, many of which I am clueless about. These are the first of several I intend to post over the next few days.
About 1" long, fit properly into a .38 Special cylinder and are one piece black plastic with what appears to be a 209 shotgun shell primer in the base. The top is rounded and closed. The only opening is for the primer. Does not appear to be anything inside. No markings on any part.
What are these? What are they for?