I don’t know “for sure” and cannot find the figure in my references, but it looks like Thai cursive to me.
I believe there is a 9mm Para cartridge with this same symbol at the top, and I believe that is “unknown” as well. Check with Lew Curtis.
I can’t currently find the reference, but I think I once saw a Nepal connection to this headstmp. Perhaps Lew has a bit more info.
this shotshell has been made by SFM for Aslan and Co in Constantinople for Ethiopian market
I sent the photo to a friend who spent many years in Ethiopia and he did not think it was Ethiopean alphabet.
Perhaps after all it is not an alphabet letter !!!
But the info :ctge made for Ethiopia through a constantinople dealer is 100 % sure.
(comming from SFM archives and orders books)