[Bull Snipe]

Walter Bell (aka Karamojo) killed 800 elephants using a 98 mauser, rechambered for a .275 Rigby cartridge with a 173 grain FMJ bullet.

[USMCPOP]

.275 Rigby is just the English name for the 7×57mm Mauser cartridge, which was developed in 1892. Bell did use John Rigby & Sons Mauser rifles.

Interesting: https://www.africahunting.com/threads/walter-d-m-bell-aka-karamojo-bell.3161/