The Škorpion vz. 61 (or Sa vz. 61 Skorpion) is a Czechoslovak machine pistol developed in 1959 by Miroslav Rybář (1924–1970) and produced under the official designation Samopal vzor 61 ("submachine gun model 1961") by the Česká zbrojovka arms factory in Uherský Brod from 1963 to 1979. Although it was developed for use with security forces, the weapon was also accepted into service with the Czechoslovak Army as a personal sidearm for lower-ranking army staff, vehicle drivers, armoured vehicle personnel and special forces. Currently the weapon is in use with the armed forces of several countries as a sidearm. A variant of the Škorpion, containing a synthetic pistol grip in place of the wooden original, was built under license in Yugoslavia, designated M84. A civilian, semi-automatic version was also produced, known as the M84A, also available in .380 ACP (9×17mm Short). History The Škorpion was developed in the late 1950s by Miroslav Rybář with the working name "model 59". The design was completed in 1961 and named "Samopal Vz. 61". It was subsequently adopted by the Czechoslovak Army and security forces, and later exported to various countries. It was also used by armed groups, including the Irish Republican Army, Irish National Liberation Army and the Italian Red Brigades. The Brigades used the Škorpion during the 1978 kidnapping of Aldo Moro, also using this weapon to kill Moro. In the 1990s the Gang de Roubaix used the Škorpion in a series of attacks in France. In 2017, the Swedish Police Authority estimated that about 50 formerly deactivated weapons from Slovakia were in circulation among criminals in Sweden. Design details Operating mechanism The Škorpion is a select-fire, straight blowback-operated weapon that fires from the closed bolt position. The cartridge used produces a very low recoil impulse and this enables simple unlocked blowback operation to be employed; there is no delay mechanism and the cartridge is supported only by the inertia of the bolt and the strength of the return springs. When fired, gas pressure drives the case back in the chamber against the resistance provided by the weight of the bolt and its two recoil springs. The bolt travels back, extracting the empty case which is then ejected straight upwards through a port in the receiver housing top cover. The Škorpion's compact dimensions were achieved by using a telescopic bolt assembly that wraps around a considerable portion of the barrel. The weapon