You might just need a new extractor. The fired casing must be properly held so that the next round pushes it up and out.
When the extractor fails, the 60/600s really jam.
A used bolt might or might not fit. They were individually fitted. Given wear and tear, there is a good chance that a used bolt won't headspace.
Finding a NOS bolt is a catch as catch can situation. It will need to be fitted.