.56 Spencer Blank cartridge

In my collection, there is a blank cartridge, I can´t identifiy, if it is a .56-56 Spencer Blank or a .56-50 Spencer Blank. I was told, that it is a 56-50 Spencer Blank. It has a wooden plug instead of a bullet.
Would it be possible, that this cartridge was made to fit to weapons of both caliber? I remember slightly, that I read something like that in the past.

Maybe somebody can help


The blank was produced by Frankford Arsenal in 1870. They are sealed with a black tar like wad.These could be used in either 56-50 or 56-52 Spencers.
I would guess it would also function in a 56-56.


Great, I am always surprised about the fast answers in this forum.
Thank you very much for confirming my assumption.