Mauser experimented with slightly more compact versions of the C-96, and eventually made a large number of them - nearly a third of the entire Mauser production run were Bolos. The terminology is not entirely standardized - I apply the name Bolo to any C-96 with a short barrel and small grip.
Here's a brief production history of "small" C-96 variants -
Cone Hammers (commercial serial number range 1 to about 14,000)
Cone hammers were made with 6, 10, or 20 shot fixed magazines. The majority have 10 shot magazines. All cone hammers have large grips. Most cone hammers have the standard 5.5" (140 mm) barrels, though a few 6 and 10 shot guns have shorter barrels - about 4.7" (120 mm).
Large Ring Hammers (commercial serial number range about 12,000 to 40,000)
These were made with 6 or 10 shot fixed magazines. Most had 5.5" barrels and large grips. But Mauser began experimenting with a more compact version of the pistol, with a 3.9" (100 mm) barrel and small grips of one pattern or another. These smaller guns have 6 or 10 shot magazines. The first small grips were oddly curved, but those were soon dropped for the more common symmetric style. Any of these smaller pistols can be called Bolos.
Small Ring Hammers
The Bolo experiment continued into early Small Ring Hammer production, in 6 or 10 shot versions, still with 3.9" barrels and of course the small grips. The commercial serial number range for these early Small Ring Hammer Bolos is around 40,000 to 43,000.
Once the Mauser design settled down and the factory began cranking out Prewar Commercials (all with 5.5" barrels, large grips, tangent sights, and 10 shot magazines), the days of small-quantity oddball production variants ended. In particular, Bolo production went on hiatus. Guns with 6 shot magazines were never made again. However, the short-barrel small-grip Bolo would be revived, 400,000 serial numbers later.
Here is a scale comparison of the biggest and smallest C-96 variants with a "typical" pistol, a Prewar Commercial.
After the Armistice, the Allies imposed restrictions on German arms production. Handguns were limited in barrel length and caliber.
Mauser began producing new pistols again in the early 1920s. The standard Mauser 7.63 mm caliber was in compliance with the Treaty of Versailles, but the 5.5" barrel was too long. Instead of making guns identical to their prewar or wartime commercials but with shorter barrels, Mauser essentially put their prewar Bolo back into production. This postwar Bolo was the standard C-96 made by Mauser through the 1920s. It was superceded by the M-30 in 1930. The M-30 reverted to the long barrel and full-sized grips.
The commercial production postwar Bolos have serial numbers from around 444,000 to 794,000. Around number 500,000 a MAUSER banner mark was added to the left side of the frame. Here are the other differences between the prewar and postwar Bolos -
These postwar Bolos account for nearly a third of all C-96 production. Any customer for new Mauser pistols throughout most of the 1920s would buy Bolos. Just who was buying large quantities of military pistols in those days isn't clear. The Bolo is associated with the Bolsheviks (although the Party had changed its name to the Communist Party in 1918 - and the bol prefix in Russian means large, an odd nickname for a relatively small gun). Although there was considerable fighting after World War One in Russia, Poland, Turkey, and Greece, that had all settled down, more or less, by 1922 or so. In any event, large numbers of Mauser pistols ended up in Russia. They must have appreciated them, as the Red Army adopted the cartridge in 1930 as the 7.62x25 mm Tokarev.
Note that although the Bolo is sometimes called the "small frame" Mauser, the only thing smaller about the frame is the grip area. Everything else - including all pieces of the lock mechanism - is exactly the same size. In fact, the internal parts are interchangeable between Bolos and full size guns.
The little barrel band under the front sight on Bolos remains inexplicable - it makes the gun look like it suffers from Luger-envy.