The 9mm Mauser was developed by Paul Mauser in 1878. It was a single-action, 6 shot revolver and was designed to compete in the German trials for their official side-arm. The Construktion 1878, or C-78 was also the only Mauser designed revolver. A problem with early revolver design was a concept called “out of time’, when the cylinder and the breech is not 100% aligned. The Mauser revolver was a superior design to fix that problem and the zig-zag grooves on the cylinder provided a channel for a spring studded cam that rotated the cylinder for an exact alignment with the breech. During the trials the zick-zack designe was deemed too complicated and the German 10.6mm Reichs Revolver, a clearly inferior design was selected. (Erlmeier, Brandt Ref. 130).

https://www.historicalfirearms.info/post/87333444338/mauser-c78-zig-zag-revolver-the-mauser

https://www.thetruthaboutguns.com/history-mauser-told-pistols/