8×64mm S

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 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).

History

At the start of the 20th century the famous German gun and ammunition designer Wilhelm Brenneke (1865–1951) was experimenting with the engineering concept of lengthening and other dimensional changes regarding standard cartridge cases like the M/88 cartridge case, then used by the German military in their Mauser 98 rifles, to obtain extra muzzle velocity.