This rare 12 gauge shotshell is a patent as you can see on the hstp.
(Bte SGDG means : Patented without any warrenty from government)
There is a steel insert with rings inside the brass case in order of blocking the cork (just over the powder) to increase the pressure.
SMI doesn’t mean Societa Metturgica Italiena but : Societe Meridionnale d’ Industries.
If some guy wants to trade shotshells, i have a lot of duplicates.
Go to vist my website : shotshells.free.fr