How old was the Wolf ammo?
Green laquer casing Wolf has not been in production for 2-3 years now, so what you bought may be old stuff that has been tossed in a old wet storage room for a few years and then brought out to sell. If that is the case then it may be just a bad lot or a messed up lot of ammo.
I once bought 180 rounds for $14 bucks, Wolf green HP ammo, some of the bullets had tarnish and even rust on the tip, when I fired the ammo the powder on some of the rounds SPARKED when it left the barrel. Poor storeage. Your ammo may have been in humid climates and the powder got wet and some of it ruined, thus when you fire the rounds not all of the powder burned and it led to weak pressure on the bolt, not pushing it hard enough back to eject and not letting it get far enough back to properly strip another round. I reccomend buying 2-3 boxes of new Wolf FMJ ammo and trying it. If it still failes then you need to work on your AK.