Here is a rare one! I have had this for awhile but just this evening realized what it was!
Braun & Bloem patented this shotshell which had a screw in “nail” that these special pins rested over. (I need a copy of this patent please!)
Jules Boché patented pins/primers that worked with this shotshell. The pin has a priming compound INSIDE it so that there was no need for a separate cap.
These pins came from the White and Munhall collection. The shotshell came from another older collection that was built around the same timeframe.
Here is the Boché patent from 1853 and 3 more additions going through 1855.