This 20 round box is missing the top, it contains 20 correct rounds with "F A 8 13" head stamps. These cartridges are designed for the Colt Double Action Revolver, Model 1909. They do not fit in a Colt 1873 because the rims are slightly larger in order to work reliably with the star extractor of the DA revolver. They can be fired in a peacemaker but must be loaded in every other chamber in order to seat fully and allow the cylinder to turn. This is an interesting variation of the 45 colt cartridge as used by the military. Free shipping.