Please post some pics or provide more information....
We really can't tell anything about it from the info you have posted....
If it is a commercial/NON-Military sort of rifle - the caliber must be stamped into the side of the barrel... Clearly visible without taking it apart.... Some of the older European guns were just marked "7mm" for 7mm Mauser....
If it is a military rifle... then someone on either this board, or a Military Collectors board could probably tell by looking at a picture of the markings what it started life as....
Barring all of this - have a Gun Smith do a chamber casting and identify the correct cartridge....
Thanks
