the 8mm mauser round is somewhere in the middle of .308 and .30-06. yes, they are very loud. next to 7.62x54r it's probably the cheapest ammo you'll find out there in surplus form. personally i don't prefer surplus ammo as it can be unreliable at times. the best thing to do with it is buy either the greek, czech, or korean surplus, take the stripper clip, save it, then pull the bullet. the bullets are good as long as their boat tails, usually steel core(some ranges don't allow steel core) but it's rare that anyone actually stores the ammo in the spam cans they came in, so the primers stop being very effective. you can not punch the pimer out and reload the case even though it's brass, it's berdan primed, i'm sorry, you're just going to have to take the brass cases to the range with you and deposit them there never to be seen again. the powder isn't worth keeping either. once you have all the bullets pulled weigh them and reload them accordingly, bear in mind they will all be different weights. you can buy a bag of new brass cases from winchester or any of the other components suppliers. you'll end up paying around 50 cents a case, or you can buy new ammo (prvi partisan is good and cheap), shoot it, yay, then reload it. then you pay around 70 cents per round and can reuse the case. when you run out of the surplus ammo you can use new bullets, i prefer sierra. .323 is the size you want(slug your barrel first to make sure), usually runs about 35 bucks for a box of 100. then you will have a tack driver of a rifle and match grade ammo for around 50 cents a round after you factor in powder and primer.
not sure if you wanted to know all that or just more about your rifle. i'm using my buddy's login as i'm not on air warrior but i love suplus weaponry and my friend thought i could help.
so many countries produced mausers and they don't exactly have the same following that mosins do so the amount of tribal knowledge and topic devoted websites if kind of lacking. hang on to it, in a couple years surplus rifles are going to be hard to come by and they last forever.