I was shooting over the weekend, and while using some Wolf steel cased ammo, there were times that hte bolt wouldn't go all the way forward. It would strip a round from the mag, but not go fully forward. It would also release (or never grab in the first place) the rim of the round. It worked fine with the few brass cased rounds we had.
It almost seemed like the bolt was rubbing on the rounds in the mag and those kept it from moving freely.
It also did it when the mags were near empty as well.
ETA: No mag wobble. But could the mag well have been ground incorectly so that the mag is pushed too far into the receiver when it is locked into place?
This may not be the problem you are having, but I had a problem with my WASR-3. There was a lot of magazine wobble.
In my case if the top of the magazine was all the way to the right and all the way down, the bolt would miss the rim. It would hit the middle of case and leave a dent in it. The solution was to raise the magazine release and add a spacer.
The spacer was easy. I took a piece of 1/8" steel and ground it to fit. It was secured by drilling and tapping two holes and using screws.
Removing the slack from the magazine catch was harder. I removed the 5mm pin. Then expanded the hole in the trigger guard upward with a Dremel. Then drilled it with a 1/4" bit. I also expanded the hole in the release downward and drilled it with the bit. I put a pin made from a 1/4 bolt. It works great.
FWIW I did the mag fix first and it did not fix the problem. So I may have been okay with just the spacer.
Also inserting the mags is smother with the spacer.
If you have the same problem and are not interested in being a home gunsmith, take it back.
I have had a very similar problem with my wasr 10. The brass rounds I have shot through it all worked beautifully but it has problems with the wolf steel case. It doesnt eject the empty or doesnt fully chamber the round.