The 9×23mm Largo (9mm Largo, 9mm Bergmann–Bayard, 9mm Bayard Long) centerfire pistol cartridge was developed in 1903 for the Bergmann–Bayard pistol. It was adopted by the Spanish and Danish militaries, with the former using it until the 1980s, when it was replaced by the 9×19mm Parabellum.
Description
The cartridge has a rimless straight-tapered brass, Berdan-primed case. The 8.2 grams (127gr) bullet is round nosed, lead-cored with a gilded steel jacket. The cartridge has a total weight of 8.75g (135.0gr). Original Spanish military loads have a muzzle velocity of 400m/s (1,300ft/s) and a muzzle energy of 656joules. According to Ian V. Hogg and John Weeks, it was the most powerful cartridge successfully used on blowback pistols, such as the Astra 400.
The 9×23mm Largo and the 9×23mm Steyr have almost identical dimensions, but they can be distinguished by the gilded jacketed bullet on the former, and the Austrian headstamp on the latter. The 9mm Largo is also very similar to the 9×23mm Winchester, but the latter should not be fired in Largo firearms due to the higher pressure generated by modern Winchester loadings.
This pistol was adopted by the Spanish army in 1905 as the "Pistola Bergmann de 9mm. modelo 1905". Unable to find a German manufacturer to complete the Spanish order for 3,000 pistols, Bergmann turned to a Belgian manufacturer, Anciens Etablissements Pieper (who used the trademark "Bayard"), to complete the order. The final pistol, modified by AEP, was known as the "Bergmann Bayard 1908", or in Spain as the "Pistola Bergmann de 9mm. modelo 1908". Although adopted in 1908, first deliveries did not take place until the next year. Meanwhile, other manufacturers such as Campo-Giro had adopted the 9mm Bergmann–Bayard round and, due to its long history of use in Spanish submachine guns, carbines and pistols, today it is most commonly known as the "9mm Largo".[citation needed]
In 1910, the Bergmann–Bayard model 1910semi-automatic pistol was adopted by the Danish military. By 1918, the Bergmann-Bayard was considered obsolete and production was discontinued, though about 1,000 pistols were assembled circa 1918−1920. The Spanish continued using the 9mm Largo in military and police weapons until the 1980s, when it was finally replaced by the 9×19mm Parabellum.
