Okay, mauserand9m, you had the correct answer.

A little persuasion in both tubes using a solid brass rod saw the action opening a bit each time until almost there, and then locked up again. The employment of a light finish carpenter’s hammer completed the job.

Here’s the evidence!

[Linked Image from i.imgur.com]

Obviously, the shells were stuck in the chambers.

[Linked Image from i.imgur.com]

Thanks to both you and Alan_C. Please carry on with the diagnosis…..

Ted