Unknown shotshell

I have this shotshell turned from solid steel.
It is headstamped “BREVETTO 15598” (patent number 15598).
Its primer is headstamped “CAP PER RID CAR” ( wich could mean "capsula per ridotte cartucce " in italain or " short range cartridge primer"
I have no info about this item

Neck diam:8,00 mm
inside neck diam:6,27 mm
shoulder diam:9,75 mm
base diam:10,07 mm
rim diam:12,00 mm
rim thick:2,04 mm
case lenght56,01 mm

Hi Pivi,
why don’t you contact the Italian INPI (in French it is : Institut National de la Propriete Industriele) (in english National Institute for Industrial Property).
It is the place where all the patents are.

Hi JP,
there is a web site like INPI in Italy but you have to be a registered user to view the data inside.However there is also an italian government web site about patents.
Since you can see data about patents registered after 1980 only,I sent them an e mail with the code.I hope they will answer me