 Most of these commercial pistols were in 7.65 Parabellum (.30 Luger) caliber, although a number of pistols were also rebarrelled to 9mm Parabellum (9x19mm).The new component parts were stamped with serial numbers to match the frame to ensure that all the fitted parts stayed together.Many thousands of these pistols were thought to have been assembled and sold between 1919 and 1923.