W.D.M. Bell used a Mauser C96 broom handle pistol in the Karamojo while ivory hunting. Famously used to shoot rapid fire several zebras when Karamojo morani were crowding in and acting threatening into his camp. Demonstrated firepower.

A Mauser C96 would be handy as a defensive weapon in the wilds and savage lands around the early 1900s. Rapid fire with the reported "most powerful handgun in the world" at the time, would be invaluable. When a lot of firearms were still single shots. Put a holster stock on it and very handy.

Regarding self defensive rapid fire weapons, I've always thought a good lever action the close in "assault rifle" of 1900. A .44/40, lots of stocking power at closer ranges.