Sounds like cheaply produced foriegn steel cased ammo to me. Probably made during war time for troops who were expected to get a shot off before dropping to their deaths at Stalingrad...
My advice would be to buy some Sellier and Bellot ammo, if you have the same problems with it, then you need to have the chamber of your rifle examined by a gunsmith, and the headspaced checked.
My advice would be to buy some Sellier and Bellot ammo, if you have the same problems with it, then you need to have the chamber of your rifle examined by a gunsmith, and the headspaced checked.