Found this in Robe, SA Australia... Think its new... But did find it not far from a UMC CO New Club shell which I think is late 1800's to early 1900's couldnt find it on line
I don't know about Australia, but here I'm the states metal
Shotgun casings are speciality order and most companies don't even make them anymore. So I'd say it has at least so age to it.
GL and HH.