hi guys, see attached. shown against a .303 for scale. 2 inches long, .55 (?) in dia. front half has only a small 3mm cavity but the bottom half is more less a full size cavity which is lined with tin (?). There appear to be 4 driving bands which show signs of rifling . There is a cannelure for crimping a case into. What on earth is it?
cheers, Dave
cheers, Dave