Bull HunterCorrectly, sir.
It can be each of that three (or even some other of the 9,3 famely).
But it should be the 9,3 x 62 for 99%.
(Exspecialy from your decribing it as a "bolt action" and a "mauser")
Your knowledge and your ability to analyze and pinpoint a calibre just by hearing it's description is most impressive . I believe you actually are correct. Do you not also own a rifle in this beautiful calibre ?