This relatively early example Savage 1904 loader has the caliber marking stamped onto the top of the tool. The vast majority of tools seen have the caliber marking on the removable die.
This later version specimen has the caliber marked on the removable die, thus allowing one tool to be used with more than one die. These tools are usually encountered in 25-35, 30-30, 38-55, 32-40 and 303 Savage. The original Savage box label is also seen.