This a authentic Civil War era dug Gallagher carbine metallic cartridge. This carbines were great weapons for the soldiers who carried them into battle atleast until their cartridge box was empty and no ammo was in sight! You can compare this one to the example seen in McKee & Mason's book in the cartidge section, labeled figure #83. The metallic casing has a beautiful brown patina and the bullet itself has oxidize to a typicall white color seen in many dug lead projectiles!