8×60mm S The 8x60mm S ( 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 . As is customary in European cartridges the 8 denotes the 8 mm bullet caliber and the 60 denotes the 60 mm ( 2 . 362 in ) case length . The 8x60mm S can , due to its 83 . 6 mm ( 3 . 291 in ) overall length , easily be chambered in standard sized Mauser 98 bolt action rifles . 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 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 ( 2 mm of lengthened body plus 1 mm of lengthened neck ) created the 8x60mm S . The 8x60mm S bullet diameter is 8 . 20 mm ( . 323 in ) as found in the 8x57mm 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 . 8x60mm . 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 . " To avoid potentially serious accidents , it is important to distinguish clearly between cartridges loaded for these two different bullet diameters , and only fire them in appropriately chambered / barrelled rifles . " Cartridge dimensions . The 8x60mm S has 4 . 16 ml ( 64 grains ) HO cartridge case capacity . A sign of the era in which the 8x60mm S was developed are the gently sloped shoulders . The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt - action rifles , under extreme conditions . 8x60mm S maximum C . I . P . cartridge dimensions . All sizes in millimeters ( mm ) . Americans would define the shoulder angle at alpha / 2 ≈ 14 . 1 degrees . The common rifling twist rate for this cartridge is 240 mm ( 1 in 9 . 45 in ) , 4 grooves , Ø lands = 7 . 89 mm , Ø grooves = 8 . 20 mm , land width = 4 . 40 mm and the primer type is large rifle . According to the official with C . I . P . ( Commission Internationale Permanente pour l ' Epreuve des Armes à Feu Portatives ) guidelines the 8x60mm S case can handle up to 405 MPa ( 58740 psi ) piezo pressure . In C . I . P . regulated countries every rifle cartridge combo has to be proofed at 125 % of this maximum C . I . P . pressure to certify for sale to consumers . Contemporary use . Mostly Mauser Gewehr 98 and Karabiner 98k rifles were rechambered for this caliber . Other rifles , not rarely based on the Mauser action , were chambered for this cartridge too . 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 longer range . 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 . No or very few rifles are produced for this round . Only two mainstream manufacturers ( RWS and Prvi Partizan ) , along with some other smaller companies like Nolasco and Sologne , continue to produce the cartridge for hunting . Loaded with short light bullets it can be used on small European game like roe deer and chamois . Loaded with long heavy bullets it can be used on big European game like boar , red deer , moose and brown bear . 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 . The 8x60mm S can be used in countries which ban civil use of former or current military ammunition . The 8x60mm S rimmed sister cartridge , the 8x60mm RS , is also not popular in central Europe for the same reasons as the 8x60mm S . The 8x60mm S is very popular in European countries like France where the possession of rifles in their original military caliber is tightly regulated : It allows French licensed gun owners to possess rifles based on the Mauser Gewehr 98 system under the less constraining " hunting rifle " category . The also rare 8x64mm S cartridge offers a comparable rechambering option for Mauser Gewehr 98 and Karabiner 98k rifles sporting 8 mm S - bores . Due to its larger case capacity the 8x64mm S chambering offers better ballistic performance than the 8x60mm S . 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 .