The brim measures 5/8" The shell diameter measures 1/2". Are there any collectors here on these? So It looks like a 50-70. what would it be dated? Value? For sale
Go here: THE CARTRIDGE COLLECTOR
and scroll down to the ".50-70 Government" cartridges. That's the informational section of the Cartridge Collector website. You'll see your exact cartridge there.
For value, see if he's got one exactly like yours for sale in the Sales section of the website.