Can you post what the year is of your CSA Vz 58, caliber, and what issue you're having. I'm trying to gather info on the ones that are defective to find a pattern. The year is on the side of the rifle near the rear sight beside the Czech Lion crest. 11 would mean it was made in 2011.
Glad the OP got all that sorted out. My .223 Vz 58 is still chirpin a long at round count 300 and its a 2013. I want to get one in 7.62 as well.
I currently do not have the rifle with me. It is with the gunsmith who offered to shoot it himself as I really do not have any more time with school bogging me down to head down to test the rifle out.
However I think it is a 2013, it is one of the chrome lined models that SFRC sold when they brought in like 4 of them.
Here is the list of the issues.
First time taking out after 10 shots gun would not fire, firing pin ended up in receiver with sheared off groove so extractor would not hold it in any longer.
Second time firing pin ends up stuck protruding out back of bolt, same issue as before with pin damage. FTE, round has a big fat hole in the primer case almost split. 40 rounds fired before this.
Third time FTE, case is stuck in chamber with big fat hole in the primer, piece of brass covering firing pin hole as well. Once brass removed everything looks ok until I notice the pin getting sort of stuck when protruding outward, I take bolt apart and long behold same issue as before, only this time enough was hanging on the piece to not fly out this time.
It would appear to be an over pressure problem. I was given smaller pistons each time. However I suspect it is a combination of over pressure and simple bolt/pin design. The original extractor did not look as beefy as the 858 extractor, in addition to this the pin looked like it was protruding a little far out (possibly why it was blowing up primers all the time). When the primer went it was enough pressure to damage the pin.
So this is where I'm at right now

. I wonder if I can get a folding stock because of the troubles I've gone through.... :/
Anyway one thing I will say is I am very impressed with the gunsmith in charge of the warranty and repair. He has to be the most knowledgeable gunsmith I have met so far. So CSA got it right there.