Years ago I was hunting up in The Bottoms of west Tennessee when I met a young man hunting with a German drilling. It was a WW II bring-back and had been given his father in payment for some dental work, his father being a dentist.
The gun was a 16 ga. double over a 7.62 x ??mm which he later learned was the metric equivalent of the .30-30 American rifle cartridge.
Beautiful gun, beautifully made.
Bob Wright