Last summer we were in Priekule searching some heavy fought over positions and the ground there was full of shrapnel of all sorts. I dug a large piece which looked like the usual artillery shrapnel, and I happen to collect large bits of shrapnel too, but when I turned the piece over I notice rifling going along it and understood it came from a gun barrel. Probably a PaK cannon as the metal isnt`t very thick. I ve cleaned the part with electrolysis and covered it in wax and it is now residing on one of my shelves.
Hope you like the result:)