Were a disproportionate number of guns having this problem made in Spain? Exactly half of the guns I have owned that were made in Spain had this problem and I have only had this problem with guns made there. Perhaps it is just a coincidence. It seems to me that in most cases I have read about online the first course of action has been to shorten the firing pins. I have personally experienced the problem with sidelocks and boxlocks, and with guns having both ejectors and extractors. All guns in question were made between the early 70's and the mid 90's. One gun would literally have to be broken over my knee to open if I used Winchester 209 primers. It was suggested that sometimes a harder primer can help mask this problem. I started using Fiocchi 615 and 616 primers and the problem went away.
