8x60/8x60mm Mauser & RWS   –   8 x 60 mm

Synonyms: 8x60mmS Mauser & RWS/ 8x60RmmJ Mauser & RWS/ 8x60RmmS Mauser & RWS/ 8x60 S Mauser / 8x60 Magnum Bombe / 8x60 S Mauser Magnum/ 8x60 RS / 8x60 R "S" Mauser Magnum / 8x60R Magnum Bombe / 8x60R "S" Hunting / 8x60R "S" Mauser/ 8 mm S Mauser/ 8,15 x 60/8 x 60 R Hunting/ 8 mm Mauser R/ 8 mm S Mauser Magnum/ 8 x 60 RS Mauser/

The 8x60mm Mauser was introduced after World War I for German civilian shooters and hunters, as they were not allowed to own rifles in military calibers like the 8x57mm Mauser.

The 8x60mmS (the S means it is intended for 8.2 mm (.323 in) groove diameter bullets) is an uncommon rimless bottlenecked centerfire cartridge of German origin, dating back to the interbellum period between World War I and World War II. The history of the cartridge and its evolution are closely related to the de-militarization of post-war Germany.

After such a devastating war as World War I, the victorious Western Powers imposed a series of harsh treaties upon the defeated nations. Inter alia, the Treaty of Versailles forbade the ownership of standard military weapons and ammunition by German civilians. However, civilian hunters didn't want to give up on this great round, so a new cartridge was designed by the German arms manufacturer Deutsche Waffen und Munitionsfabriken (DWM). Extending the 7.92x57mm Mauser cartridge case by 3 mm created the 8x60mmS. By the European common cartridge’s nomenclature, the 8 denotes the 8 mm bullet caliber, and the 60 denotes the 60 mm (2.362 in) case length.

The 8x60mm S bullet diameter is 8.20 mm (.323 in), as found in the 8x57mm IS. The 8x60mmS can, due to its 83.6 mm (3.291 in) overall length, easily be chambered in standard-sized Mauser 98 bolt action rifles. As the new cartridge used the same bullet, 8x57 or 8x57R rifles can be easily converted to their appropriate 8x60 derivative with a simple chamber lengthening job (reamed out by 2 mm plus 1 mm of neck extension) not costly, and many were so altered, in order to be legally licensed.

The 8x60mm S offers, compared to its parent cartridge, the 8x57mm IS, about 1 to 2% extra muzzle velocity due to its slightly larger case capacity and higher maximum operating pressure. This results in a flatter trajectory and better performance at a longer range.

This operation was easily performed on Gewehr 98 and Karabiner 98k rifles. Since this chamber reaming operation is also possible for earlier I-bore rifles, 8x60mm chambered rifles (without the S or any other further additions) also exist. 8x60mm rifles sport the earlier tighter 8.07 mm (.318 in) I-bore as found in the 8x57mm I.

The 8x60mm is a confusing round because it comes in a confusing variety of types and loads. Like the 8x57mm Mauser, the 8x60mm Mauser was and still is produced in 4 versions: 8x60mmJ, 8x60mmS, 8x60RmmJ and 8x60RmmS. Most people assume the "J" (0.318) patrone was introduced first, but it wasn't the "S" bullet (0.323). This was probably to make use of the many surplus 0.318 bore rifles then available in Europe. Mostly Mauser Gewehr 98 and Karabiner 98k rifles were rechambered for this caliber. While the 8x60mm S case could handle up to 405 MPa (58,740 psi) pressure, both J (.318" diameter) and S (.323" diameter, versions were available in both rimmed and rimless case styles in all load types.

Except this, there are three more variations of the above and include a standard and a magnum loading, as well as one called the Magnum-Bombe loads. The case dimensions for Standard, Magnum and the Magnum-Bombe loadings are all the same. The only difference is powder, velocity, and bullet weight. In the standard load, the 8x60mm is approximately the equivalent of the .30-06. The heaviest magnum loads are approximate to the .300 H&H performance level. African hunters did not consider it any better than the .300 H&H.

To avoid potentially serious accidents, it is important to distinguish clearly between cartridges loaded for these two different bullet diameters and only fire them inappropriately chambered/barreled rifles.

The 8x60mm S offers very good penetrating ability due to a fast twist rate that enables it to fire long, heavy bullets with a high sectional density. It is a popular round in Europe and has been used to some extent in Africa, although most African hunters do not consider it any better than the .300 H&H. It has sufficient power for North American big game and could be used for anything the .30-06 can handle. On the heavy game, such as moose, elk, or grizzly bear, it would have the edge over the .30-06 if one used maximum loads.

The 8x60mm S is very popular in European countries like France, where the possession of rifles in their original military caliber is tightly regulated. The 8x60mm S can be used in countries that ban the civil use of former or current military caliber.

The popularity of the 8x60mm S peaked just after World War I and continued throughout the 1930s and 1940s. Today the cartridge is almost obsolete. Only two mainstream manufacturers (RWS and Prvi Partizan), continue to produce the cartridge for hunting. Handloaders can also produce this round by altering a .30-06 Springfield case and using a standard 8 mm bullet. Prvi Partizan is a major supplier of brass components for European 8x60mm S Handloaders.