|Warning! The .425 Westley Richards Magnum is a proprietary cartridge introduced by Westley Richards in 1909. It has a rebated rim of smaller diameter than the body of the case to fit the standard-diameter Mauser bolt face. It was used in bolt-action and double rifles.
The 425 was designed as a knockdown cartridge for use against dangerous game. It proved to be one of the best for that purpose and was very effective on elephant.
Only one weight bullet was made, but it was available in solid, copper-capped and hollowpoint-capped types. The solid was for maximum penetration, the copper-capped for limited expansion combined with good penetration. The hollowpoint-capped was for quick expansion on thin-skinned game. The 425 has about the same power as the 458 Winchester Magnum and is over-powered for North American big game. It is the largest of what the British call the large-medium bore class.