Very few pre 1912 German shotguns were Nitro Proofed. As I understand it German law of the era required the amount of smokeless powder used be increased over the standard in the same proportion as was Black Powder in proof. This was not pressure related but simply powder charge wt. Doubling a charge of black & doubling a charge of smokeless does not give the same results. Most pre 1912 guns found with the Crown/N mark will show an extremely light load as the service load. This was done to keep it from being destroyed in proof.
These Sauer/VL&D guns were pre 1912.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra