I talk with a friend about it, he is a full fledged cartridge collector. find it in volume 3 of Josef Mötz "Austrian Military Cartridges" where its named 9,3x60 Peterlongo

https://www.waffenbuecher.com/publikatio...atronen-band-3/

anyway I believe the book is wrong here, the rifle is a .375, there is the advertisement for a 9,5 mm Peterlongo. Don't think there was another 9,3x60 Peterlongo, the world was not big enough for two similar proprietary cartridges.