Question: Q:The 7.92×57mm Mauser rifle cartridge was used by which country's military in the 20th century?

An intermediate cartridge is a rifle/carbine cartridge that is less powerful than typical full-power battle rifle cartridges, such as the .303 British, 7.62×54mmR, 7.92×57mm Mauser, .30-06 Springfield or 7.62×51mm NATO, but still has significantly longer effective range than pistol cartridges.  As their recoil is significantly reduced compared to high power rifle cartridges, fully automatic rifles firing intermediate cartridges are relatively easy to control.  However, even though less powerful than a traditional full-power rifle cartridge, the ballistics are still sufficient for an effective range of 250 – , which are the maximum typical engagement ranges in modern combat.  This allowed for the development of the assault rifle, a selective fire weapon that is more compact and lighter than rifles that fire full power cartridges.  The first intermediate cartridge to see widespread service was the German 7.92×33mm Kurz used in the StG 44.  Other notable examples include the Soviet 7.62×39mm used in the AK-47 and AKM series, 5.45x39mm first used in the AK-74, and the American 5.56×45mm NATO cartridge first used in the M16. <SEP> A world war, as it is commonly understood, is a large-scale war involving many of the countries of the world or many of the most powerful and populous ones.  While a variety of global conflicts have been subjectively deemed "world wars", such as the Cold War and the War on Terror, the term is widely and generally accepted only as it is retrospectively applied to two major international conflicts that occurred during the 20th century: World War I (1914–1918) and World War II (1939–1945).  World wars span multiple countries on multiple continents, with battles fought in many theaters. <SEP>  The 7.92×57mm Mauser cartridge was adopted by the German Empire in 1903/1905, and was the German service cartridge in both World Wars. The 7.92×57mm Mauser (designated as the 8mm Mauser or 8×57mm by the SAAMI and 8 × 57 IS by the C.I.P.) is a rimless bottlenecked rifle cartridge.  In its day, the 7.92×57mm Mauser cartridge was one of the world’s most popular military cartridges.  In the 21st century it is still a popular sport and hunting cartridge that is factory-produced in Europe and the United States. <SEP> The 7×57mm cartridge, also known as the 7mm Mauser, 7×57mm Mauser, 7mm Spanish Mauser in the USA and .275 Rigby in the United Kingdom 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.  It is recognised as a milestone in modern cartridge design, and although now obsolete as a military cartridge, it remains in widespread international use as a sporting round.  The 7×57mm has been described as "a ballistician's delight".  Many sporting rifles in this calibre were made by British riflemakers, among whom John Rigby was prominent; and, catering for the British preference for calibres to be designated in inches, Rigby called this chambering the .275 bore after the measurement of a 7 mm rifle's bore across the lands.