The 7.5×57mm MAS or 7.5×58mm mle 1924c was a short-lived French rifle cartridge that was introduced in the mid-1920s to replace the 8×50mmR Lebel, although it itself was soon replaced with the 7.5×54mm French round, that served the French for decades to come until France, along with the rest of NATO, adopted the standard NATO calibers, 5.56×45mm NATO and 7.62×51mm NATO. Wikipedia