I would check gap between cylinder and barrel forcing cone. If it is too tigth, the gun will jam when firing as the cylinder will suffer a small dillatation form heat. It should have at least 0,1mm of gap or it wont work properly.
printing paper is about 0,1mm and should run free between cylinder and cone when the hammer is atfull cock and loaded with empty cases..
It is easy to solve with a fine file with some touches in the forcing cone just keeping it well flat over it and wont affect accuracy.
It is the way they do the final fitting sometimes in the factory.