Mine was a revolver. Astra 680: it was recently discussed in a thread. The cause was dead simple: grit and powder residue build up on the flat crane-to-frame mating surface.
However, until it was identified the revolver was useless: impossible to pull back the trigger.
One wipe and I was back in business!
When the right to effective self-defence is denied, that right to self-defence which remains is essentially symbolic.
Freedom: Please enjoy responsibly.
Karma. Another word for revolver: because what goes around, comes around!