The 3rd Generation: From the vz. 61 Skorpion Submachine Gun to the CZ Scorpion EVO 3 A1

The 3rd Generation: From the vz. 61 Skorpion Submachine Gun to the CZ Scorpion EVO 3 A1


The Czech arms industry made a great impact in 20th century weaponry history with a large range of remarkable products.  Probably the most original of them all was a “special submachine gun” named the Skorpion, a successful effort for covering the gap between service pistols and traditional submachine guns chambered in pistol cartridges.  The Skorpion, in its initial, less powerful caliber, i.e. 7.65mm Browning (.32 Auto), has not met modern security unit’s requirements for some years, much less that of the armed forces; nevertheless its position as a globally respected legend has not been changed by this in any way.  It is therefore no surprise that Česká zbrojovka a.s., the manufacturer of the Skorpion, registered the name Scorpion as a trade mark in the 1990s and that it is currently using it now for the third generation of compact automatic weapons made in the town of Uherský Brod.

At the beginning of the initial Skorpion development was an interest of the then Czechoslovak Ministry of Interior in “a special submachine gun for service purposes” in cal. 7.65mm Browning (.32 ACP), which would be suitable both for so called special security activities, and for unified armament of the State Security and Public Security members.

Let us recall that the State Security (StB) was the secret political police of then socialist Czechoslovakia and the Public Security was the Czechoslovak version of uniformed police; under “special security activities” it is again necessary to look for intelligence and counterintelligence activities.  What kind of automatic weapon could suit such different requirements?  The Czechoslovak Ministry of Interior had about it a surprisingly clear vision, which it summarized in 1958 in the following requirements:

– cal. 7.65mm Browning (.32 ACP),
– weight 1 to 1.2 kg,
– overall length with shoulder stock folded 250 mm,
– overall length with shoulder stock extended 440 mm,
– height with pistol grip 150 mm,
– effective range of fire 100 m,
– two types of magazines – one for 8 to 10 rounds, the other for 20 to 25 rounds.
– besides fully automatic fire there should be provision to shoot also in single shots so “that this SMG could also fulfill the function of a pistol.”

It is obvious that such a clear and original vision had to go through a comprehensive research and analysis phase, the content of which we can only guess.  An interesting detail was the caliber chosen as it is highly unusual for an automatic weapon and additionally not quite suitable due to its relatively low performance and cartridge case with protruding head rim.  From today’s perspective one wonders if the choice of the 7.65mm Browning (.32 ACP) cartridge, which is often considered to be the greatest shortcoming of Skorpion submachine gun, what the Ministry of Interior had in their explicit intentions.  This cartridge on one hand represented a standard pistol caliber of the Czechoslovak Security Forces, and on the other hand it had several features which were ideal just for “special security activities.”  And just for this reason even the Czech Army did not mind it – but more about this later.

Task for Mr. Miroslav Rybá et al
In the first half of the 1950s within the centralization of the nationalized industry in Czechoslovakia came the end of the famous independent design offices of individual arms factories.  Instead, the Communist Party of Czechoslovakia decided to build a large specialized research and development centre, which was initially named Konstrukta Brno (after its place of residence in the City of Brno) and by the end of 1955 the elite of the Czechoslovak design engineers concentrated there dealt with military weapons and ammunition up to 30mm and anti-tank recoilless weaponry.  (Concurrently there was formed a small design centre in Prague specializing in the development of civilian firearms.  This centre however lost its independence quite quickly.)

New strict rules on confidentiality have been put into force for contracting weapon development and, besides other things, it has been out of question that the Ministry of Interior itself would address relevant design centre.  The application should first have to be submitted to the Czechoslovak Ministry of National Defence (MND), and in the case of the future Skorpion submachine gun this happened in the fall of 1958.  Relevant experts from MND found this idea of their colleagues from the Interior very interesting and the decision had been made that after production commenced, the purchases would also be by the Czechoslovak Peoples Army.  For the start, military personnel claimed only a small number of units for their intelligence units, however right in the beginning they came with important comments, observations and requirements, which had a substantial influence on the final version of the Skorpion.

The requirement of the Ministry of National Defence to produce a “special submachine gun” (among soldiers also known as “multi-purpose”) was sent to the Brno firearms research and development centre at the time when the engineers on the site were swamped with work.  All the senior engineers were busy completing other projects, such as the UK vz. 59 multi-purpose machine gun or the vz. 58 submachine gun (which in fact was and is the assault rifle, but the Czech military terminology did not accept this term at that time).  Due to their overload, the task to develop a new special submachine gun was assigned to Ing. Miroslav Rybář (1924–1970) who worked at the small-bore arms design department.  This turned out to be an extremely fortunate decision.

Ing. Rybář was a talented engineer with exceptionally deep technical skills and credentials from civil and military area.  He had been involved in firearms design since 1948, but had until then served only as a team member, supervised by senior engineers.  The Skorpion was to be his first individual project, the pinnacle of his career that, unfortunately, ended prematurely.

Unlike previous generations of firearms designers, who considered mathematical calculations a dull part of their work and delegated them gladly to others, Rybář started with a comprehensive theoretical analysis.  In fact, he wrote his doctoral thesis on the Skorpion, and presented it successfully at the Military Technical Academy in Brno in 1958.  With such a sound background, the development of the new type of a special submachine gun, aptly named Skorpion, proceeded really fast: lasting only from February 1959, to summer of 1961.

It is worth mentioning that although Rybář was undoubtedly the main architect of this new weapon he was not alone who was involved in this project.  The team counted as many as 13 engineers and we have to mention above all Otakar Galaš (1904–1968).  Galaš was well known as a designer of hunting and sniper rifles (the most famous worldwide being ZG 47 rifle).  Galaš contributed substantially to the development of the Skorpion – not only he was in charge of the sound suppressors’ elaboration and the weapon’s accessories, but having enlarged the barrel bore twist rate he also satisfactorily solved the accuracy of the 7.65mm Browning (.32 ACP) cartridge at distances between 25 to 150 m.  Moreover he became an excellent advocate of the new weapon.  Galaš found a very original way of demonstrating that the Skorpion could be carried covertly underneath one’s clothing: he came to a meeting bringing the submachine gun stuck in the shoulder holster underneath his jacket without anyone noticing it.  During the meeting, when he suddenly opened his jacket and took out the gun, there was no doubt that the Skorpion was suitable for concealed carry.  Jiří Čermák (1926–2006), another legend among firearms designers, who had his name indelibly recorded in the history of weaponry with already mentioned vz. 58 submachine gun, also helped Rybář with this project.  Although Čermák did not work on the Skorpion directly, he was the co-author of one small, but very smart structural element and he claimed the key idea of implementing rate-reducing mechanism.  However, the practicalities of design engineering were taken over by Rybář.

Between Pistol and Submachine Gun
The outcome of Rybář and his team work was a weapon that combined in a unique way the features of both submachine gun and pistol.  The common feature with the submachine guns was first of all the blowback (unlocked) breech, a magazine located in front of the trigger guard and folding stock that enabled shooting from the shoulder.  At the same time the Skorpion used the same cartridge as pistols, and to the certain extent, it was provided with a similar hammer-striking mechanism and the option to fire with the bolt in the forward position, which rendered shooting much more accurate when firing single shots.

For shooting in bursts, the high rate of fire and the muzzle climb were successfully tamed by the mechanical rate-reducer, which provided full control of the weapon also in the automatic mode.  (A certain role has to be attributed also to the weapon’s weight, which slightly exceeded initial requirement by the Ministry of interior, but still with a little exertion enables efficient single-hand hold and with centre of gravity moved forward.)  Various rate reducing mechanisms had been known before, but Rybář´s patent belongs to the ones which were particularly well designed – quite simple be it in design or manufacturing process and at the same time absolutely reliable.

The basic version of the Skorpion was at the end covered by five Czechoslovak patents on behalf of Rybář.  Another four were registered for the following development of variants in other calibres, one of which was additionally used in the series production.  Apart from the rate reducer, the patents covered the technical solutions of the shoulder stock, the trigger mechanism, the spring–loaded bolt stop, and so called retaining plate of the trigger unit which prevented hammer stop pin from falling out (co-author J. Čermák).

The original concept was applied particularly to the wire shoulder stock made from aluminium alloy.  The actual folding was realized around the rear part of the trigger unit with option for easy shoulder stock removal.  The length and stiffness of the shoulder stock due to the weapon compactness are in the limits of practical applicability, nevertheless, the manner of fixation and release in both utmost positions made for a wonderfully simple solution.  Ingeniously, the simple way of unfolding shoulder stock is with a single strike of the palm from the non-shooting hand, from below to the butt, whereupon the rest of the work is smoothly and reliably done by the shoulder stock pin spring, it is hard to find any comparisons.