US rim fire casing

[gardenscott]

Found this rim fire casing in a very old area near where I found a seated quarter. It's smaller than a 44. Any ideas?

 

[cheese]

Looks like a .22 to me.

 

[TheCannonballGuy]

A cartridge-casing's "headstamp" (base-marking) saying US in RAISED lettering means it was manufactured by the United States Cartridge Company (a privately-owned manufacturer, not a US Army Arsenal) sometime between 1885 and 1908. Afterward, the headstamp lettering saying US was indented.