This is a metal detector find. I found this damaged casing and perhaps also the bullet about 15 feet away. The base of the casing has some marking but it’s very difficult to read - part of it might read “0”. Any help is appreciated! As a new user, I seem to be limited to only one image - here you go.
A photo of the actual case (side view and case head), along with information about what country / location you found this would be helpful.
From COAL and RIM dim.,seems .455 Webley Revolver.
Again, Photos and where found.