7 . 65×21mm Parabellum The 7 . 65×21mm Parabellum ( designated as the 7 , 65 Parabellum by the C . I . P . and also known as . 30 Luger and 7 . 65mm Luger ) is a pistol cartridge that was introduced in 1898 by German arms manufacturer Deutsche Waffen und Munitionsfabriken ( DWM ) for their new Pistol Parabellum . The primary designers were firearms designers Georg Luger and Hugo Borchardt , who developed the round from the earlier 7 . 65×25mm Borchardt while working at DWM . Development . In 1897 , the C - 93 Borchardt pistol was submitted for testing to the Swiss Military Trials Committee . The Committee found the Borchardt too heavy and unwieldy to serve as a military sidearm . Georg Luger was tasked by DWM with improving upon the Borchardt pistol . He developed the 7 . 65x21mm Parabellum cartridge from the 7 . 65×25mm Borchardt . By shortening the cartridge case , Luger was able to design a narrower grip , and the toggle action required a shorter stroke than in the original Borchardt design . A transitional Borchardt - Luger model in the new caliber was submitted to the Swiss commission in 1898 . After further improvements , the final result became the DWM Pistole - Parabellum ( ' Luger pistol ' ) . The loading for the new cartridge was standardized and mass production began in 1900 - 1901 in DWM ' s factory in Karlsruhe , Germany . Around 1903 , a separate load was developed for Parabellum carbines , with approximately 20 % more powder ( increased from the standard 0 . 32 - 0 . 35 g to 0 . 4 g ) and a blackened cartridge case . This carbine load was manufactured until sometime after World War I . History and Usage . Since its introduction , 7 . 65x21mm Parabellum ammunition has been manufactured in several countries for both domestic use and for export , including Germany , Switzerland , Finland , France , Portugal , the United Kingdom and the United States . With the adoption of the Luger pistol in 1900 , the 7 . 65mm Luger became the standard pistol cartridge of the Swiss Army until the late 1940s . The later sidearm of the Swiss military , the SIG P210 , was also manufactured in this caliber , but only for civilian use ; Swiss military issues of the P210 were chambered in 9×19mm Parabellum . The 7 . 65mm Parabellum was replaced by the German army with the 9×19mm Parabellum cartridge . This involved simply expanding the bottleneck of the 7 . 65mm Luger cartridge to accept a 9mm bullet . Due to the almost identical case width , rim width , and overall length of the cartridges , most 7 . 65mm Parabellum firearms can be converted to 9mm Parabellum with only a change of barrel , and vice versa . The Luger pistol in 7 . 65mm was adopted by the Finnish in 1923 with the designation " Parabellum Pistooli 23 , " abbreviated m / 23 . About 8000 pistols were delivered , but few survived the war . Many of these pistols were rebarreled to 9mm , and a limited quantity remained in storage until 1980 for arming non - combat personnel . In addition to the Luger Parabellum and the SIG P210 , several other handguns have been manufactured in this caliber , mainly for commercial sale in countries that restrict civilian use of contemporary military calibers such as 9mm Parabellum . Examples include the Astra A - 80 , Benelli B80 , Beretta 92 , Browning Hi - Power , Mamba , some models of the Ruger P series and the SIG Sauer P220 . A handful of submachine gun s have been manufactured in this caliber , notably the SIG Bergmann 1920 ( the licensed Swiss version of the Bergmann MP - 18 / 1 ) , the Flieger - Doppelpistole 1919 , the M / Neuhausen MKMS , the Austrian MP34 and the Suomi M - 26 . Cartridge dimensions . The 7 . 65×21mm Parabellum has 0 . 93 ml ( 14 . 3 grains HO ) cartridge case capacity . 7 . 65×21mm Parabellum maximum C . I . P . cartridge dimensions . All sizes in millimeters ( mm ) . The common rifling twist rate for this cartridge is 275 mm ( 1 in 10 . 83 in ) , 4 grooves , ø lands = 7 . 62 mm , ø grooves = 7 . 83 mm , land width = 3 . 05 mm and the primer type is small pistol . This cartridge headspaces on the shoulder of the case . According to the official C . I . P . ( Commission internationale permanente pour l ' épreuve des armes à feu portatives ) guidelines the 7 . 65×21mm Parabellum case can handle up to piezo pressure . In C . I . P . regulated countries every pistol cartridge combo has to be proofed at 130 % of this maximum C . I . P . pressure to certify for sale to consumers .