It looks like one of the mauser sporters that were so prevalent in the country between the 1st and 2nd world wars. Those double set triggers can be real dreams when you get used to them. It isn't rare or valuable but it is a fine rifle and capable of very good accuracy if the bore is in good shape.
They came in many different calibres. 9.3mm, 8mm, 7mm and some in 6.5mm. There may even be others.
If it were mine, I would clean it up, won't devalue it, and shoot it. If your eyes are good enough, don't d&t it. If they're like mine, you'll need a scope. Shoot it and enjoy it. It's more than likely chambered in 8x57mauser. Get it checked out first though. I'm surprised it's not marked on the left side of the barrel.