12mm Shot Pinfire Cartridge

Size: 12mm Shot
Headstamp: 0
Manufacturer: Armamentarium - Delft, Netherlands
Additional Info: This is attributed as being made at the Armamentarium ("arsenal") in Delft, Netherlands. I would love any documentation or info on this. It is a shot load.
picture of Armamentarium pinfire cartridge
Picture of Armamentarium headstamp