|9×20mm Browning Long|
|Place of origin||Belgium|
|Designer||John Moses Browning|
|Manufacturer||Fabrique Nationale de Herstal|
|Case type||semi-rimmed, straight|
|Bullet diameter||.3578 max. (9.09mm max.)|
|Neck diameter||.379" nom. (9.68mm max.)|
|Base diameter||.380" nom. (9.72mm max.)|
|Rim diameter||.404 in (10.3 mm)|
|Case length||20 mm (0.79 in)|
|Overall length||1.10 in (28 mm)|
|Primer type||Small pistol|
|Source(s): Rifles and Machine Guns  Prvi Partizan |
9mm Browning Long is similar to the 9×19mm Parabellum, but has a slightly longer casing and is semi-rimmed; the cartridge headspaces on the rim. The cartridge was developed by FN to be used in the blowback-operated Model 1903, a scaled-up version of the Colt 1903. Using a more powerful cartridge, such as the 9×19mm Parabellum, would have required a locked-breech design. Ammunition was produced in Belgium, France, England, Sweden and the United States. There was some production in Germany during World War I for the Ottoman Empire, and the cartridge was also used in South Africa.
The cartridge is now obsolete and it is hard to find reloadable brass for this ammunition; one option handloaders have is to take the .38 Super and shorten it to the right length.
Prvi Partizan in Serbia manufactured 9mm Browning Long ammunition into the 2000s. The Prvi full metal jacket bullet weighs 7 grams (108 gr.) with a muzzle velocity of 350 metres (1,150 ft) per second.
- Powder: 4.5 grains N340.
- Bullet: 110 grains Norma J
- Length: 1.09 in
- Velocity: 815 ft/s (248) m/s
- Melvin, M., Capt., USMCR. Rifles and Machine Guns, p.385. New York,: William Morrow & Company, 1944.
- Prvi Partizan 
- Janson, O. "Browning pistol M1903 becomes Swedish Pistol m/1907"
- Janson, O. "Equipment, holsters and ammunition for m/1907"
- Wilson, R. K. Textbook of Automatic Pistols, pp.237–238. Plantersville, S.C.: Small Arms Technical Publishing Company, 1943.
- "9mm Browning Long". prvi partizan. Retrieved 26 October 2017.
- 9mm Browning Long loading data at Gun Loads website
- "Ladeboken web site". Archived from the original on 2020-10-28. Retrieved 2010-08-15.