Prompted by the 1972 Munich Olympics Massacre , the German police decided to replace the .32 ACP Walther PP with a similarly sized but more effective 9 × 19 mm Parabellum pistol . The new firearm was to meet the following requirements : chamber the 9 × 19 mm Parabellum cartridge , weigh no more than , the pistol 's dimensions would not exceed 180 × 130 × 34 mm , it should have a muzzle energy of no less than 500 J and a service life of at least 10,000-rounds . The pistol was also to be fully ambidextrous , safe to carry with a loaded chamber ( both holstered and concealed in a pocket ) , and able to be quickly drawn and instantly ready to fire . As a result of a competitive bid the German police forces selected three different pistols into service : the Swiss SIG Sauer P225 ( designated the P6 ) and two German designs — the P7 ( officially designated the PSP ) and the Walther P5
1972 Munich Olympics Massacre
Munich massacre
Heckler & Koch P7