Re: Authentic revolver percussion cap?
Generally, the gauge of copper, nature of the "explosive" fulminate dot, and sometimes may be the ribbing can be a general clue...
The problem in IDing, IMHO, can lie in the not only the large numbers of pistol caps made before, during, and after the War, but also in how long the same type of cap was used for percussion muzzleloading rifles AFTER the War.
Not to mention the widespread "modern revival" of reenacting arms.
I have a tin of copper musket caps from the Civil War Bicentennial.
I also have some well preserved, "dug" pistol caps that do not visually appear any different from the "German" caps sitting on my shelf since the 1980's.
In gleichem Schritt und Tritt, Curt Schmidt
Not a real Civil War reenactor, I only portray one on boards and fora.
I do not portray a Civil War soldier, I merely interpret one.