8×64mm S

Type

Rifle

Place of origin

Germany

Service history

In service

Never issued

Production history

Designer

Wilhelm Brenneke

Designed

1912

Produced

1912 - present

Variants

8×65mmR S (rimmed)

Specifications

Parent case

none

Case type

Rimless, bottleneck

Bullet diameter

8.22 mm (0.324 in)

Neck diameter

8.96 mm (0.353 in)

Shoulder diameter

10.85 mm (0.427 in)

Base diameter

11.95 mm (0.470 in)

Rim diameter

12.00 mm (0.472 in)

Rim thickness

1.30 mm (0.051 in)

Case length

64.00 mm (2.520 in)

Overall length

87.50 mm (3.445 in)

Case capacity

4.51 cm³ (69.6 gr H₂O)

Rifling twist

240 mm (1-9.449")

Primer type

Large rifle

Maximum pressure

405 MPa (58,700 psi)

Ballistic performance

Bullet mass/type	Velocity	Energy
12.7 g (196 gr) S&B SPCE	810 m/s (2,700 ft/s)	4,166 J (3,073 ft·lbf)
12.7 g (196 gr) S&B HPC	815 m/s (2,670 ft/s)	4,218 J (3,111 ft·lbf)
12.8 g (198 gr) Brenneke TIG	848 m/s (2,780 ft/s)	4,600 J (3,400 ft·lbf)
14.25 g (220 gr) DWM Starkmantel	800 m/s (2,600 ft/s)	4,562 J (3,365 ft·lbf)

Test barrel length: 600 mm (23.62 in)

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).

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.

In 1912 Brenneke designed the 8×64mm S cartridge. This cartridge is an example of a de novo rifle cartridge (the 8×64mm S and 6.5×64mm have no other cartridge as parent case) intended as a ballistic upgrade option for the Mauser Gewehr 98 rifles that were then standard issue in the German military. The exteriour cartridge case dimensions like overall length and slightly larger case head diameter compared to the German 8×57mm IS military cartridge coupled with a moderate increase in maximum pressure were chosen with easy conversion of Gewehr 98 rifles for the 8×64mm S in mind. Brenneke hoped that he could achieve a major success with this round designed in an age when military doctrine expected rifle shots at ranges up to 800 to 1000 m (875 to 1094 yards). The German military chose however to stick to their 8×57mm IS rifle cartridge avoiding rechambering their service rifles for a larger and heavier cartridge that due to its more favourable bore area to case volume ratio ballistically slightly outperforms the .30-06 Springfield cartridge introduced by the United States Army in 1906.

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Wikipedia