Fact is...any gun that hinges on a pin where the metal can wear away from either the pin itself or on the hook will, if used enough, become loose on the face and require some sort of fix. A Darne will never become loose, despite what "others" aka "Geno" say. Still have never seen or heard (from a credible source") of a loose Darne. jOe, there are no loose Darnes. When it comes to Darnes, the only thing I've ever seen wrong with one that would keep it from being operated safely is severe neglect. The spiral springs inside the breach block come from a Lebel rifle, they are hell for stout and if they happen to break...they still keep on working. I'm sorry gang, until someone shows up with a legitimately worn out Darne, and by legitimate I mean worn out from normal, everyday use, not neglect, you are going to have a hard time convincing anyone who cares that there is a stronger more robust double gun out there.
I've seen a few worn out Purdeys though, even sleeved ones. I know where there's one right now waiting to be restocked, it wobbles on the face and sounds like worn out cv joints on a car, and it needs new mainsprings too, but the gun sure does look pretty on the outside.