Shotshell 18

any info on the manufacturer ?

There is a variation of this headstamp with no -'s. Most of the MUNICAR headstamps were MUNICAR FRANCE, therefore I presume it was made by or for a French firm. You are in France, who is it?

The fact it is written “France” doesn’t mean the manufacturer is french.
A lot of shotshells after WWII were imported, often from Italy.
Most of the time, they writte : "import