Something that continues to confuse me around what I've read here about this gun is the chambering issue.

Is it true that a chamber reamer has recently been run through those chambers, and still after that's been done ammo won't chamber in the gun?

What is the problem with the chambers?
What is it about the fit that won't allow a round to chamber?

also
When you speak of 'sling/no sling' are you saying that some of the shots fired were shot with sling tension as if the rifle were being shot in the fashion that one would shoot a rifle during High Power rifle competition?

and
Aren't double rifles meant to be shot with the barrels firmly grasped in the support hand, forward of the forend wood?

--Tinker