This is called the Czechoslovakian “9 mm cylindrical cartridge” or 9 mm ostrych naboju – valcovych made for the experimental ZB 47 SMG made by Zbrojovka Brno. The ZB-47, also known as the Samopal 47, was designed by Václav Holek in two variations. Ten guns were chambered for the straight case 9mm Nábojù-Válcových and ten were made 9mm Parabellum. This cartridge differs from a normal 9mm Parabellum in that it does not have a tapered case but a straight case so it will not fit in a 9mm Parabellum. It was produced by Sellier & Bellot at Vlasim in 1947.

Picture From the August 1999 issue of Střelecký Magazín​