The ZB37 began in 1930 as a design by none other than classic Czech arms designer Vaclav Holek. The Czechoslovakian military was still using the Schwarzlose heavy MG, and wanted something to replace it. To fill all the roles intended, there would eventually be three different models of the ZB37 - one for infantry, one for fortresses, and one for vehicle mounting.

Note that the factory designation for this gun at Brno began as the ZB50, and iterated to the final version being the ZB50. However, it was identified by the military as the ZB37 (for 1937, the year of adoption).

After a series of redesigns, an early version of the gun is finally adopted in 1935 as the ZB35. A series of improvements leads to the final ZB37 model. About 500 of the early ZB35s were produced, and most of these were used to fill export sale contracts. By the time World War Two begins, the Czechoslovak military has about 5,000 of the guns in its possession.

Interestingly, the gun uses a hybrid recoil and gas operating system, with a tilting bolt. It has two rates of fire that can be chosen, and uses the rear spade grips as the charging handle. It is belt fed, using continuous 100- and 200-round metallic belts and chambered for the 8x57mm Mauser cartridge.

During the war, both German and British forces made substantial use of the ZB37. The Germans purchased ongoing production from Brno, and the British had actually purchased a production license before the war began. For the British, the gun was called the BESA and used in several armored vehicles (still in 8mm Mauser) - with about 57,000 being made during the war. A number of export sales were also made, including Romania, Persia, China, and several others. In 1946 another 3,000 were ordered and manufactured for fortress use in the Czech Republic, serving until the end of Communist control of the country.

Thanks to Sellier & Bellot for giving me access to this example to film for you!