You can go to the cartridge collector's website and look there. The headstamp is Yugo, can't tell the caliber from that picture.
Lol.But were they illegal aliens? Enquiring minds and all that.
Looks like 8MM to me as well.
I agree, Berdan.Definitely Prvi Partizan of Ulzice Yugoslavia (now Serbia).
Probably 8mm Mauser.
Probably Berdan primed.
Look in the case and see if it's got one central flash hole (Boxer) or 2 (sometimes 1 or 3) that are slightly off center (Berdan).
Yep, 8x57.