Why is "7x57mm Mauser" trending?

Wikipedia Overview

The 7×57mm Mauser 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 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 cartridge is today often erroneously referred to as the ".275 Rigby", however neither Rigby & Sons nor Kynoch sold the cartridge in boxes labeled .275 Rigby - instead it was always marked ".275 bore" (Rigby) or 7mm Mauser (Kynoch) and it is doubtful the cartridge was ever referred to as the ".275 Rigby" during its golden period.