The 7X57mm Mauser rifle and cartridge sure got the attention of the British Military, during the Anglo-Boer War in South Africa. (and the U.S. Military during the 'Spanish War').

In the early 1900s, lighter Spitzer BT projectiles, driven at higher velocities, were replacing heavy RN bullets, for most of the World's military powers.

The Pattern 1913 'Enfield' rifles, produced in 'Trial Numbers' at Vickers, Ltd., fired a .282 inch, 165 grain, projectile at 2,800 FPS. As 'reincarnated' pointed out, WW1 stopped this development.

Vickers focused on making Machineguns! (Gauges, tooling, and blueprints came to U.S. manufacturers to produce .303" Pattern 1914 rifles on contract for Britain).

Photo of rare Pattern 1913, .276 Enfield cartridge packet, and comparison of cartridges:

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