I had always thought a cross bolt on a side by side was called a Greener cross bolt and the cross bolt lock on an over under was a Kerstan cross bolt. I also thought that Kerstan cross bolt consisted of two ears, one on each side of the barrel. Lately I've run across the two eared version being called a Double Kerstan and now I see the spelling of Koerstan. I had believed the the cross bolt on an O/U to a German invention. So I wonder now if I have been spelling it wrong of there is some subtle differences of which I am not aware. Some enlightenment on the subject would be very appreciated. Thanks!
