It turns out that the factory ammunition being used in the Mauser C96 was soft nosed. Churchill himself says so explicitly. The following is his his evaluation of the weapon. It is from chapter 25 of The River War, which is his chapter in military matters. The entire chapter makes excellent reading but this is from Page 351 The River War: An Historical Account Of The Reconquest Of The Soudan by Churchill, Volume II 1899.
The River War Vol 2 at Internet Archive
"Among the more recent improvements in firearms none should attract more attention than the invention of the magazine pistol. Several kinds are already in the market, and all possess in varying degrees the same advantages. Perhaps the best and the best-known is the Mauser pattern. I write as almost the only British officer who has used this, weapon in actual war. Its superiority to the revolver is 'plain. It fires ten rounds, whereas the revolver fires but six. It is sighted to 1,000 yards, and shoots effectively to 800. The revolver is never of any use beyond fifty yards, although its bullet carries much farther. The pistol is self-loading, self-cocking, self-ejecting. Its rate of fire is as fast as the trigger can be pulled. Its muzzle velocity is almost double that of the older weapon. It can be recharged with ten rounds on a clip almost as quickly as a single cartridge can be loaded into a revolver. By a cunning arrangement the recoil is utilised to eject, cock, and re-load; so that the hand remains steady while successive shots are fired. It is cheaper and lighter. Finally, it is furnished with a case of light wood instead of leather, and this fits into the pistol-butt, making a handy and accurate carbine. In spite of all these complications, the weapon did not get out of order in a country where the desert sand affects all machinery.
This is not a prospectus: nor shall I disguise the disadvantage. It does not fire a sufficiently heavy bullet.
Although the small projectile with its expansive tip and high velocity has shattered bones into splinters, there is greater safety in a larger bore. It is, however, so much easier to shoot with the Mauser pistol than with the revolver, that even this objection is modified, for it is better to hit with a small bullet than to miss with a big one: and when a weapon is made on the same principle and on a larger scale, the revolver will follow the arquebus into the museums of ancient arms; and who shall say that the magazine pistol with its carbine fitting will not oust the trooper's sword as well as the officer’s revolver? "