The iconic Mauser “broom handle” pistol was popular on both sides of the Russian civil war. Although not as ubiquitous as the Nagant revolver, the Mauser was renowned for its quality and power. In the novel, Anna carries the Mauser, as did many Cheka agents of the period.
The German arms manufacturer Mauser produced the C96 from 1896 to 1937. Before WWI, it was widely sold around the world both to governments and the general public. Mauser manufactured close to one million of these pistols, and there were also numerous licensed and unlicensed versions produced in other countries.
The design had many innovative features including strip and box magazines and a wooden holster that could be attached to the pistol grip as a stock, converting the pistol into a rifle.
In this pre-WWI Russian ad, the Mauser pistol with the wooden stock and a cleaning kit is advertised for 50 Rubles.