Niklas,
I read that original post & found the chamber cast very interesting. I've never seen a chamber like that & I have not answers, only more questions.
That taper at the front of the chamber was unique, but the "forcing cone" was so abrupt that it shouldn't really be called a cone - more of a step. It looked to me that the original paper shells must have been thick enough at the neck that it evened out the step.
It might be optimized for the paper shells and card/fiber wads of 1900. In the US, brass shells were common at that time & were much thinner than paper shells. I would think there might be a problem with the larger wads, needed to seal the thinner brass shells, catching on the step. I wonder if there would be a problem with our thinner modern plastic shells and plastic wads.
Certainly I'd feed better shooting the gun if that step were not there.
Regards, Rn
