I re-read your original post about the problem and gu position. The rear section of the two piece firing pin drops down out of alignment with the channel when the gun is opened. It would seem that it is not being pushed back in alignment when action is closed. Due to wear of maybe something under the spring in the that pushes down on the rear section of firing pin in the bolt
https://www.youtube.com/watch?v=MGJcPVSHOAw
