The 7x57mm Mauser was designed in 1893 by Paul Mauser and is also known as the 7mm Spanish Mauser, .275 Rigby, along with 7mm Mauser. The case is an original design with a rimless, bottleneck type case that fits a .285 inch bullet on a .325 inch neck with a case length of 2.244 inches and overall length of 3.071 inches. It has a large rifle primer with a 1:8.66 twist.
The ballistic performance for the 7.57 Mauser based off three grain types for muzzle velocity are 3,000 ft/s (139 gr), 2,600 ft/s (162 gr), 2,500 ft/s (173 gr RWS HMK), and 2,300 ft/s (173 gr Military load). The 7x57 Mauser has become a popular hunting rifle for shooters, and has been used by militaries such as the Spanish government.
The 7x57 Mauser has a almost flat trajectory along with a moderate recoil when fired. In addition it has good wound penetration on game up to the size of an elephant, which has been noted by such hunters as Walter Bell. Bell was famous for his African Safari hunting expeditions during the early 1900's, but later caliber rounds have replaced big game hunting cartridges such as the 7x57 Mauser. Now it used on game in North America up to the size of moose in most cases.
The 7×57mm Mauser (designated as the 7 mm Mauser or 7×57mm by the SAAMI and 7 × 57 by the C.I.P.) is a first-generation smokeless powder rimless bottlenecked rifle cartridge. It was developed by Paul Mauser of the Mauser company in 1892 and adopted as a military cartridge by Spain in 1893. It was subsequently adopted by several other countries as the standard military cartridge, and although now obsolete as a military cartridge, it remains in widespread international use as a sporting round. The 7×57 Mauser (originally known in Britain as the .275) was a popular stalking cartridge and sporting rifles in this chambering were made by the famous British riflemakers, such as John Rigby Holland and Holland, Westley Richards and others. British cartridge nomenclature designated caliber in inches, and the cartridge was known as the .275 bore after the measurement of a 7 mm rifle's bore across the lands.
The 7×57mm cartridge has 3.90 ml (60 grains H2O) cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt-action rifles and machine guns alike, under extreme conditions.
The ballistics of the 7×57mm became popular with deer and plains game hunters. The relatively flat trajectory and manageable recoil ensured its place as a sportsman's cartridge. The 7×57mm can offer very good penetrating ability due to a fast twist rate that enables it to fire long, heavy bullets with a high sectional density. This made it popular in Africa, where it was used on animals up to and including elephants, for which it was particularly favoured by noted ivory hunter W.D.M. "Karamojo" Bell, who shot about 800 African elephants with 1893 pattern 7×57mm military ball ammunition using Rigby Mauser 98 rifles, when most ivory hunters were using larger-caliber rifles. Bell selected the cartridge for moderate recoil, and relied on the 11.2-gram (172.8 gr) long round-nosed military full metal jacket bullets for penetration.
