I was thinking the same thing; old fired shells, or maybe snap caps? My Fox Sterlingworth 16 locked up on me on a recent South Dakota trip; the strikers in the snap caps were too low and the firing pins were hung up. Fortunately it was my back up gun and I didn't need it. Got it open later and raised the strikers. But actually, I'm thinking the "gummed up" thing is the most obvious problem.

Make sure it's not loaded before there is any trigger pulling.

Im usually like that as well when it comes to shipping a gun , however I think on double guns especially vintage ones its best to send them to a expert they arent ar15s where just anyone can work on them.

John,
Try this:

"I have had the same experiences as Harry C with insufficient rim recess. My fix for getting the gun to open was to place the receiver and barrels in a well padded vice ( bottom of receiver and top of barrels at the breach) and carefully and slowly tighten. I often would hear a click, the top lever would move free and when removed the gun would open. I now have a complete set of reamers."
http://parkerguns.org/forums/showthr...barrels&page=2

This is from a 2019 post on the same problem. It is possible gun was put away because it would not open, so, cases may still be in chambers.
Bob Jurewicz
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