The 8x64mm S (also unofficially known as the 8x64mm S Brenneke) (the S means it is intended for 8.2 mm (.323 in) groove diameter bullets) is a rimless bottlenecked centerfire cartridge developed as a military service round for the German Army who never issued it. As is customary in European cartridges the 8 denotes the 8 mm bullet caliber and the 64 denotes the 64 mm (2.52 in) case length. The 8x64mm is a hunting cartridge in central Europe and can due to its 87.5 mm (3.445 in) overall length fairly easily be chambered in standard sized Mauser 98 bolt action rifles.