Measurements of the case (length, diameter, rim size, etc) would be a tremendous help.
Without them, there is really no way to be sure.
As a guess, based on the pics, it could be a .45-70 "blank", or Line Throwing Cartridge. Or it could be a shot cartridge that someone made in a .45-70 case.
it is about the right size. Or it could be some other case with close dimensions. Without measurements, you can't be certain just by eye.
I don't recognize the headstamp. Sorry.