I have a 10 year old used #2, 28 ga that experiences intermittent difficulty in opening after firing. It appears that the firing pins are extending into contact with the primer, as there is a light score mark on the 6 o'clock position of the fired primer. I can open the breech, however, more leverage pressure than normal is needed, and then the extractors kick the shells quite away, which is a nuisance - especially when at a clays station. This occurs about 80% of the time. When the top lever is pushed to open, there is a solid click all the time. This seems to be an internal problem, as the pins are free to move within their bosses. Anyone have an idea of the cause?