The 20×138mmB cartridge or Long Solothurn is a type of ammunition used mainly for anti-aircraft and anti-tank weapons during World War II. The designation means the caliber is 20 mm, the length of the cartridge case is 138 mm and B indicates it is a belted case. The loaded cartridge weighs 10.7 ounces (300 g).
Three 20×138B cartridges and a 37 mm shell
|Place of origin|
|Used by||Switzerland, Germany, Italy, Finland, Poland|
|Wars||World War II|
|Case type||Bottleneck, belted|
|Case length||137.4 mm|
The 20×138mmB cartridge was initially created by the Swiss Solothurn company in the early 1930s.
The 20×138mmB cartridge is used in the following weapons:
- Johnson, Melvin M., Jr. (1944). Rifles and Machine Guns. William Morrow and Company. p. 385.