Indeed, as Hoot indicated that is a M-95 straight pull

by John K., Monday, September 09, 2013, 16:30 (4037 days ago) @ Frank S

of WWI Austro-Hungarian fame. Obviously not in original trim.

Uses proprietary en-bloc clips. The Nazis issued them as police and secondary weapons during WWII. Some Nazi-marked ammo floating around not too many years ago. The original 8x56R cartridge pushed a 206gr slug to around 2400fps.

As Hoot also mentioned, it is not a far reach to reconfigure one of these to 30-40 Krag.