also, assume it is corrosive primed...
And clean your gun accordingly. If non-corrosive, no harm done, just a little more work. But most surplus ammo from eastern nations is corrosive primed.
The US ended corrosive priming of its military ammo beginning in the 1950s, but other nations didn't until much, much later, and some may still be making new ammo with corrosive priming. Assume any foreign surplus ammo to be corrosive, act accordingly, and you won't damage your gun.
If you don't already know, corrosive priming leaves behind chemical salts from the priming compound, that will absorb and trap water against the steel, causing rapid rust. They can be cleaned away with water, and then followed by the normal cleaning routine, all will be well.