I was out at the range today with a friend to test out my project SKS. I had to replace the valve with a Muray's oversized one. I can tell you that it worked great and cured my cycling issue.
As I was zeroing in my scope and trying it out, all of a sudden it quit cycling the bolt. The bolt was not locked up but it would only pull back about 1 1/2". I didn't want to break it down all the way there at the range so finished up with my new AR builds and then headed home. Got settled and then pulled the SKS up onto the bench and dismantled it.
What I found was quite strange to me and it is the first time in my 10 years of working on and customizing SKSs(most of those professionally) that I have run across this situation.
I removed the stock, mag, and sling and then the Chicago bolt for the Magwedge rail and pivoted it out of the way. As I removed the receiver cover out drops the firing pin which was bent. I inspected it and other than being bent it looked fine.(no cracks, dings, scrapes, or breaks anywhere)
So, I proceeded to remove the retaining pin expecting it to be broken or something. What I found was a nice groove in it where the notch of the firing pin had pushed over it when it came out the back of the bolt. Bolt appears to be okay, but looks like I'm going to have to buy a new pin and retainer.
Anybody else ever run into this?