Cartridge identification

No idea what this might be. Overal lenght approximately 34,29 mm/1,350 inch, caselenght is about .866/ 22 mm and rim diameter .485/12,33mm. Caliber with paper approxiamtely .367. Lead bullet.
I’ve two of these. EP 07 (photo) and EP 0. Once more: anybody?



This is a Belgian 9 mm Nagant cartridge for ordnance double barreled pistols and revolvers (also pistol-carbines). It was made by the École de pyrotechnie at Anvers, and packed in 6 round boxes labeled “Cartouches à balle pour pistolet et revolver” plus date.

Sounds very reasonable. Thank you from the other side of the world. Fede, the day I win the jackpot, I’ll visit you!

Recently I found this 9mm Belgian Nagant round with what I thought was an interesting headstamp.