I have had this cartridge that I thought was a Murata. Was told by someone with more knowledge than me that it was not, since it does not have the protected primer. I have looked for small caliber rifles with a tubular magazine and only come up with the Mauser-Kropatchek (8x60R) and the Murata (8x53R). Anyone have an idea what it is?
The dimensions are:
Bullet diam .326