64-8

The 8×64mm S (also unofficially known as the 8×64mm 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 8×64mm is a hunting cartridge in central Europe and can due to its 87.5 mm (3.445 in) maximal overall length fairly easily be chambered in standard sized military Mauser Gewehr 98 bolt-action rifles. In such military M98 bolt actions the magazine boxes, however, have to be adapted by a competent gunsmith to function properly with the 8×64mm S cartridge, since the M98 internal magazine boxes feature an internal magazine length of 84 mm (3.31 in).

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