Its in my humble cartridge collection but I don't have a clue what it is. Sits next to .45 acp.
Rim diameter: .570"
head diameter: .489"
case length: 1.412"
bullet diameter: .430"
https://images34.fotki.com/v1675/pho...MG_0113-vi.jpg
https://images34.fotki.com/v1633/pho...MG_0115-vi.jpg