The Russians captured lots of Mauser 98 variants. The markings alone may not tell you much. Or possibly a Yugo made Mauser. Germany forced production of 98s and 98k rifles in captured factories such as Poland and Czechoslovakia.

Picture at be useful in narrowing things down though.

 

Pictures would help, but sounds like Russian capture 98 to me !...............

 

I have some pictures, but the quality is not the best-I'll take some pictures and post them.Actually, it looks like a Mauser k98k bolt with a straight bolt handle.It can be used on a kar 98k without problems.Only a few slavic people uses cyrillic:Russians, Bielorussian,Bulgarians,Serbs,Ukrainians.In my opinion, It was made probably made in Cz, then captured by the yugos.I have only one question:Had the cz mauser 98 a straight bolt action(the vz 24 must be excluded)?

 

The pictures are here
https://drive.google.com/folderview?id=0B279azG2GUuFSUI4ZEZKT0puNmM&usp=sharing

 

That is a Mauser 98 bolt !....................Probably Russian capture..............

 

Ok, it is a Mauser 98 bolt....but what Mauser exactly?

Some more considerations(Assuming that it is a Gewehr 98 bolt):
1)We know that the Gewehr 98 has such bolt.
2)The G 98 was produced since 1898 till 1918.
3)It belongs to a rifle that is chambered in 7.92×57mm Mauser, so it must be post 1905.
4)The G98 has seen service in both WW1(extensive use) and WW2(limited use).

The questions that still remain are the following:
-Is it possible to know when the weapon was captured(If it was captured)?
-Are there any other countries that manufactured such bolts between 1905 and 1945?
-Is it possible that the weapon belongs to another arsenal(e.g.Kingdom of Serbia, since they also use cyrillic, ordered small quantities of G98 and used the 8mm Mauser cartridge) and that it was captured but exported?
-What do you know about the markings?