7.92 x 33 mm
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7.92 x 33 mm is a rifle cartridge developed in Germany prior to and during World War II. The ammunition is also referred to as 7.92 mm Kurz (Kurz being German for short) and was specifically intended for development of the assault rifle (Sturmgewehr in German). Few weapons used this round among them being the Sturmgewehr 44 and Volkssturmgewehr 1-5; and a number of German prototype weapons made during the World War II and a small number of prototype weapons made in other countries after war. The round was developed as a compromise between the longer 7.92 mm rifle round and the 9 mm pistol round, and is known as an intermediate cartridge.
The 7.92 Kurz was the same caliber as the standard 7.92 x 57 mm German infantry round, which was employed by German infantry in their Mauser 98 rifles, as well as the machine guns employed by infantry units. With a case length of 33 mm, the cartridge was substantially shorter and delivered less recoil than standard rifle ammunition. This meant it could be fired in fully automatic mode in a receiver that weighed closer to that of a standard rifle than a machinegun, yet still had much greater velocity and stopping power than the 9 mm Parabellum, which was the standard for German submachine guns.
Another issue that this cartridge addressed was the late WWII shortage of brass. This cartridge used a steel case. Brass has a certain amount of elasticity, and when a cartridge was fired the brass case would expand and seal the chamber until the pressure in the barrel had dropped. After the pressure dropped, then the brass case would retract slightly which made extraction easier. Because the new steel cases did not retract well and were occasionally difficult to extract, this cartridge was given a cone-shaped case instead of the traditional cylindrical case in order to make extraction more reliable, which also led to the distinctive curved magazine for weapons that used this cartridge. The cases were typically painted to prevent corrosion.
Prior to the development of the Kurz round and its associated weapons, two basic weapons existed for equipping the regular infantry rifleman. The battle rifle (a bolt-action rifle in most armies of the time) was the standard equipment, usually incorporating good accuracy and killing power, but having a very limited rate of fire. The submachine gun was a newer piece of equipment, which offered a deadly rate of fire at automatic, but was of very limited range and killing power due to the pistol round (usually 9 mm) it fired. While it did not match the range and accuracy of a traditional bolt-action rifle, it more than made up for it in volume of fire over the ranges most likely to see infantry combat, and had the killing power to be deadly. As an effective, intermediate-sized cartridge, the Kurz round was a key evolution in the development of the assault rifle class of firearm.
After World War II, the cartridge was tested and was used in prototype rifles in countries including Argentina and Belgium in the late 1940s and early 1950s. The first FN FAL prototype was designed to fire the 7.92 mm Kurz. After the war the 7.92 Kurz cartridge was manufactured by the GDR, ČSSR and Egypt.
Demand for the ammunition still exists, as the StG 44 is currently in service with the Lebanese Forces as well as irregular forces in some countries in the Horn of Africa and the Middle East. 7.92 Kurz ammunition is currently manufactured by the Prvi Partizan factory [1] in Užice, Serbia.