The .416 Rigby or 10.6x74 was first manufactured in 1911 by the British Rigby rifle and ammunition-making company. It was the first .416 rifle caliber, and rifles were built on magnum-length 1898 Mauser actions.
John Rigby & Co. designed the .416 Rigby to use a large cartridge case for a reason. The .416 Rigby is an enormous round by American standards, but when the British brought it out they designed it, like many of their big game cartridges, as a very powerful but low-pressure cartridge. British cartridges designed in this era to use smokeless powder were loaded with Cordite, which was very sensitive to temperature, showing large spikes in pressure in the hot climates of India and Africa. Under such conditions, brass cartridge cases have a tendency to stick in rifle chambers after firing because chamber pressure becomes too high, and a stuck case will jam the gun. A jam could be fatal if a lion, tiger, rhino, or other potentially charging beast was near by. The huge cartridge case allows the .416 Rigby to give good performance while keeping chamber pressure down.
Most .416 Rigby factory-loaded ammunition pushes a 400 grain bullet in the neighborhood of 2,300 feet per second (700 m/s). Additionally, it doesn't have the tremendous recoil of other large cartridges such as the .460 Weatherby Magnum. Recently-offered lighter-weight bullets, affordable reloading brass, and reasonably priced American and imported rifles have made this caliber increasingly popular for hunting large game in the United States.
The fairly modern .460 Weatherby Magnum is based on a belted version of the older .416 Rigby case, but is loaded to far higher pressures. The .416 Remington Magnum, using a much smaller case, will equal the veteran .416 Rigby in performance, again thanks to higher pressure.
Until recently, the use of .416 cartridges was mostly confined to Africa, where they were used primarily on dangerous or "thick-skinned" large game such as rhino, elephant and Cape buffalo.