8×60mm S

The 8×60mm S is a rimless bottlenecked centerfire cartridge of German origin, dating back to the interbellum period between World War I and World War II. The bore has the same dimensions as the German 7.92×57mm Mauser service cartridge (designated as "S-bore"). The 8×60mm S can, due to its 83.6 mm (3.291 in) overall length, easily be chambered in standard sized Mauser 98 bolt-action rifles. In such military M98 bolt actions internal magazine boxes feature a magazine length of 84 mm (3.307 in).

History

After World War I, the Allied forces signed the Treaty of Versailles. This Treaty prohibited the use of standard military weapons and ammunition by Germany. However, civilian hunters didn't want to give up on this round, so a new cartridge was designed by the German arms manufacturer Deutsche Waffen und Munitionsfabriken (DWM). Extending the 7.92×57mm Mauser cartridge case by 3 mm (2 mm of lengthened body plus 1 mm of lengthened neck) created the 8×60mm S. The 8×60mm S bullet diameter is 8.22 mm (.323 in) as found in the 8×57mm IS.

The new cartridge used the same bullet and therefore only the chamber of the rifle had to be modified (reamed out by 2 mm plus 1 mm of neck extension) to accommodate the slightly longer case. This operation was easily performed on Gewehr 98 and Karabiner 98k rifles. It also meant that owners of rifles so re-chambered could not then be used as an "ad hoc" reserve to the German Army (that was one of the issues of concern at Versailles of reserves of male civilians disguised as rifle club members with their own privately owned rifles - being trained as reinforcements in time of war as the German Army was by that Treaty limited not only to 100,000 men but also to the number of rifles it could possess) as standard military ammunition could not now be safely fired in rifles so converted.

8×60mm

Since this chamber reaming operation is also possible for earlier I-bore rifles, 8×60mm chambered rifles (without the S or any other further additions) also exist.