9mm Parabellum was designed by Austrian George Luger 10mm Auto was designed by FFV Norma AB of Sweden 5.56 NATO was developed in Belgium by FN Herstal, as was 5.7mm 7.62×39mm was developed by the Soviets
These European cartridges all use metric measurements
.223 Remington, .308 Winchester, .30-06 Springfield, .40 Smith & Wesson, .22lr, .357 Smith & Wesson Magnum, .44 Remington Magnum are all American made cartridges that use decimals of Imperial measurements Original designer’s name gets includes because, well, capitalism lol
I think one of the few exceptions might be 6.5mm Creedmoor, developed by Hornady