I gave up on Wolf ammo last year and use only Yugo surplus ammo for target practice now. It's slightly corrosive, but FAR more consistant and accurate. After a few hundred rounds of it and NO flyers, I was convinced that this was the way to go. I was given some American made 7.62X39 ammo at the range (Winchester, I think, not sure) and it was no more consistant than the Komada I've been using. The Komada actually proved to be better in my rifle. Only handloads are more accurate, but not by much due to the rounds limitations. It is not a "Sniper" round.
Ok. I used a reciever cover type mount for a year and took it off. Two problems. The first was the brass beat the @#$%%$# out of the bottom of the scope. This could be some of your jamming issues. The second problem was that the mount allows the front to move upward. I watched my son shot at a deer. The bullet struck the ground half way to the deer. Took the rifle and found that the scope was pointing up because the mount was a POS.
Get the mount that attaches to the side of the reciever.
No matter what the brass will hit the scope.
SKS's wern't made for scopes.
I didn't use such a big scope that it would go over where the shell ejects. I'm using a ClearI 100 yrd Mil Dot scope. Nothing fancy. I never had the shell hit that scope.
I put a Bushnell Trophy red dot on a cover mount with the side screws , an M1 Garand cheekpiece and a rubber buttpad for added LOP on mine.
Thing is tho , I can shoot just as well using the irons. The butt pad was about the best thing I did for my SKS.