The 20×138mmB or Long Solothurn cartridge 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 .
History
The 20×138mmB cartridge was developed by the Waffenfabrik Solothurn, a Swiss front company of Rheinmetall in the early 1930s from a less powerful cartridge 20×105mmB cartridge.
Weapon platforms The 20×138mmB cartridge is used in the following weapons:
Switzerland Solothurn anti-tank rifles: S-18/1000 and S-18/1100 Solothurn ST-5 20mm AA Gun
Germany FlaK 30 and FlaK 38 single-barrel, and Flakvierling quadruple-barrel anti-aircraft guns KwK 30 and KwK 38 vehicle-mounted weapons MG C/30L aircraft gun
Italy Cannone-Mitragliera da 20/65 modello 35 (Breda) Cannone-Mitragliera da 20/70 (Scotti)
Finland Lahti L-39 anti-tank rifle Lahti L-40 anti-aircraft gun
Poland Nkm wz.38 FK anti-tank vehicle-mounted gun
References