When you get to talking about military Mauser bolt actions, there are a million different variations out there because most of Europe (and the rest of the world at one time or the other, for that matter) used them. To be able to tell what you have, you're going to have to do some research. Mauser made these gun to the specs of the country ordering them and every country wanted something a little different. The differences can be VERY minor at times.
Heck, at one time there were 3 different countries (Portugal, Greece and Sweden, if I remember correctly) just in Europe that were using a Mauser chambered in a 6.5mm cartridge and none of the cartridges were interchangeable. Whole wars have been fought with nothing but Mausers being used by both sides. That's how prevalent they were. Not all are Mauser made guns either. The Czechs (Brno) and the Swedes (Huskvarna) both had contracts to build them and there may have been others (the Belgians, too, maybe? Or they may have done that post WW2 but I have seen Belgian Mausers). For example, all the Persian '98 long rifles (WWI style) that came on the market back around '95 were Czech made and had never been issued since their production in the '30's.
I know the Spanish used a '96 (?) Mauser rechambered from 8mm into .308 for the Guardia for a long time. It was a short rifle or carbine with a turned down bolt- I don't remember which at the moment. They came onto the surplus market back in the mid '90's. Israel also rechambered a lot of the guns they got back in the late '40's into .308 after it was adopted. Since the Israelis were mostly getting battle field pickups and whatever else they could lay their hands on from the world arms market, there's literally no telling what the original nation of origin may have been, although a lot of what they ended up with were 98k's originally in 8x57.
Rechambering was pretty common. My Portuguese Mauser started life in a 6.5mm but was barrelled and chambered for 8x57 later on. (I still kick my self for not picking up a Colombian Mauser in .30-'06 back then but I didn't like the steel cup style butt plate they came with.) The Portuguese swapped over to 8mm back in the '40's because they could get materiel from the Nazis- even though they were neutral during WW2- and later the Spanish.
