I found this object at a flea market. I don’t think it is even a cartridge, but for 50 pence I bought it anyway.
“Calibre” inside of measurement of case mouth is roughly 16.2mm, case length is 60mm and rim diameter is 34mm.
It has the letters “HRH” scratched into the base. The rim/base part appears to be made from a separate piece of brass.
Does anyone have any opinions, or know this thing’s real intended use?
Thanks for any info.