Monday 9 May 2022

Undercover Gun Runners

Czech anti-tank rifles fell into German hands after the annexation of Czechoslovakia, but the Germans got their hands on similar weapons designed in another European country in a different way. When it comes to Swiss (and other European) arms makers, the question of who made the order, who produced it, and who it was sold to often does not have a simple answer.

Trendsetters from Zurich

One example of this situation is the 20 mm autocannon developed by Reinhold Becker in Germany during WW1. After the end of the war, disarmament, and the Treaty of Versailles, the gun suddenly resurfaced in neutral Switzerland with the then unknown Oerlikon company. Before too long, the name Oerlikon became synonymous with the concept of small autocannons. German and Anglo-American pilots would be shooting at each other from descendants of Becker's guns.

An Oerlikon AA gun crew on a British warship, April 1943, Scapa Flow.

Oerlikon's main product was AA and aircraft guns, but the Swiss did not forget about the needs of infantry. Thankfully, it did not require a very large or powerful anti-tank rifle to knock out a thinly armoured tanks with bulletproof armour that made up the majority of armoured vehicles of the time.

The Schweres Selbtsladen Gewehr 32 or SSG 32 (heavy self-loading rifle model 1932) appeared in 1932. The 20 mm 20x70 mmRB round penetrated 20 mm of armour at 100 meters. That was all that was needed. According to some sources, the weapon debuted in the Chaco War between Bolivia and Paraguay. 

A few years later, Swiss designers adapted their design for a more powerful 20x110 mmRB round. A number of complaints from end users were also addressed in this weapon. The bipod was moved, the trigger mechanism was improved, the shoulder stock shock absorber was improved. Despite the more powerful round, the new SSG 36 rifle was more comfortable for the rifleman. Both rifles used various magazines of 5, 10, or even 15 rounds.


SSG 32

SSG 36


20x70 mmRB

20x110 mmRB


1450 mm

1727 mm

Barrel length

750 mm

840 mm


33 kg

36 kg

Rate of fire

8-10 RPM

Effective range

500 m

Muzzle velocity

555 m/s

750 m/s

Penetration at normal



100 m

20 mm

27 mm

300 m

17 mm

23 mm

500 m

15 mm

19 mm

The anti-tank rifles found their buyers, but compared to the immensely successful AA and aircraft gun business this was not a very profitable direction for Swiss arms designers. If needed, their AA guns could fire at ground targets as well as airborne ones anyway.

The British went the furthest with this idea, mounting their 1-pounder AA gun on a tracked chassis. The result was called a light anti-tank gun. However, the British quickly realized that a 20 mm caliber was insufficient and developed their idea further into the 2-pounder Anti-tank Gun Carrier with a 40 mm gun.

SSG 36 anti-tank rifles.

Some number of Oerlikon anti-tank rifles served in the Wehrmacht, but there is no verified information about their use. Perhaps the Germans were simply against the idea of using non-standard ammunition.

Since Oerlikon was located in neutral Switzerland, it could sell its weapons left and right, frequently supplying both sides. This didn't stop the Americans from blacklisting former German officer and then respectable Swiss industrialist Emil Bührle for trading with the Nazis and then urgently clearing his name when his 80 mm rockets were needed by the Allies. Switzerland's geographic position made it difficult to sell guns to anyone other than Germany during the war.

Anti-tank rifles for satellite states

Another Swiss company, Waffenfabrik Solothurn A.G., occupied a much less gray area. Solothurn was bought out by Rheinmetall in 1929 in order to circumvent restrictions set by the Treaty of Versailles. The Germans were initially planning to set up in the Netherlands with Hollandische Industrie und Handels Mattschaps, but this project did not take off like its Swiss cousin. Interestingly enough, the penetration data obtained by the USSR in the early 1930s came from these Dutch guns. 

In addition to the Steyr-Solothurn S1-100 SMG (formerly Rheinmetall's MP 19 designed by Louis Stange) Solothurn began working on anti-tank rifles. The first attempt was with the S18-100 anti-tank rifle. As with their competitors from Oerlikon, the gun was based on a late WW1 autocannon, except this one was designed by Heinrich Erhard. Solothurn transformed Erhard's unrefined gun into the ST-5, which their new German masters were very interested in.

Solothurn S18-1000 semiautomatic anti-tank rifle.

Erhard's weapon was created to use the 20x70 mm round. Despite the same dimensions as Becker's round, this was a novel design. In order to overtake their competitors, Solothurn opted for the more powerful 20x105 mmB round. The first S18-100 anti-tank rifle was chambered in this caliber. However, the Swiss preferred the longer and more powerful 20x138 mmB.

Customers lined up for the S18-1000 quite eagerly, including Germany. The Germans designates this weapon Pz.B.41(s). Another variant of the Solothurn called S18-1100 also supported fully automatic fire, allowing it to be used as an AA gun when installed on a special mount. This was more of a tacit admission that anti-tank rifles are becoming useless at their primary role: fighting tanks.

Since Soviet documents make no mention of Hungarian or Romanian anti-tank riflemen, it is reasonable to assume that the Finns used these rifles most effectively among Germany's allies. A batch of S18-1000 anti-tank rifles was purchased in August of 1939, but after that either all new S18-1000s went straight to the Wehrmacht or the Finns were scared off by the price of a Swiss product. Finland only purchased the cheaper S18-100 from then on, or rather the S18-154 variant.

A German infantryman with the Pz.B.41 (s) anti-tank rifle.

Even getting those weapons was not easy. As per the Molotov-Ribbentrop Pact, the Germans impeded shipments of arms to Finland. Rheinmetall's masters prohibited it from selling its arms to just anyone. As a result, the sale of a dozen S18-154 turned into a true spy thriller. The rifles were officially sold to the Swiss army, and made their way north through the Finnish embassy in Italy.

By the time the rifles arrived it was already spring, the Winter War was over, but the Finns estimated that returning these rifles would not be worth the hassle. A year later the S18-154 saw use during the fighting for the Hanko peninsula. The Finns treated their weapons carefully and the last S18-154s were sold in the late 1950s to Interarmco, an American company known for its very peculiar list of interests. This episode is best illustrated by a line from Finché c'è guerra c'è speranza: "You should know these weapons. Of course, we lost with them in '45"

Judging by a lack of standard markings on the Finnish Solothurns, the Swiss either handed them an experimental batch of rifles, or didn't stamp them as an insurance policy so that it would be harder to trace them back to the company in case they were discovered.

Finnish soldiers with a Solothurn S18-154 rifle. The photo illustrates the wide variety of weapons used by the Finns. One soldier is wearing either an M35 or M40 German helmet, another has the Finnish M40 that copied a Swedish design. A captured Soviet SVT-40 rifle is leaning against the wall of the trench.

Finally, Finland purchased a single Solothurn S18-1100 in 1942 for trials. Judging by the lack of further interest, the trials did not go well. The Finns provide the following data for the S18-154 (the penetration data is taken from several sources and part of the information is only applicable to the Solothurn S18-1000).
  • Caliber: 20x105 mmB Short Solothurn
  • Length: 1760 mm
  • Barrel length: 930 mm
  • Weight without a magazine: 40 kg
  • Weight fully loaded: 45 kg
  • Magazine capacity: 5 or 10 rounds
  • Muzzle velocity: 860-910 m/s
  • Penetration at 90 degrees:
    • 35 mm at 100 meters
    • 27 mm at 300 meters
    • 23 mm at 500 meters
  • Penetration at 60 degrees:
    • 20 mm at 100 meters
    • 15 mm at 500 meters
Heavy option or variant #3

The third Swiss anti-tank rifle was developed by engineers in Bern. This weapon was converted from a cannon, not an aircraft or anti-aircraft cannon, but a tank one. The 24 mm Panzerwagenkanone 38 was developed by the Chief Engineer of Waffenfabrik Bern Adolf Furrer to equip LTH (Panzerwagen 39) light tanks. This gun was also used in pillboxes. Swiss infantry took a look at this weapon and reached the conclusion that a more mobile version of this weapon was a good idea. It was not too difficult to install the gun on a wheeled carriage, although calling the Tankbüchse 41 (Tb 41) a rifle was a bit of a stretch.

24 mm heavy anti-tank rifle developed at Waffenfabrik Bern.

The Tb 41 was a pretty good "heavy anti-tank rifle" or light anti-tank gun for the early 1940s. It could fight light tanks and even present a danger to medium ones. However, by 1943 when the gun was available in large numbers, the armour of tanks was much thicker. Nevertheless, the Tb 41 remained in production until 1945.

Totalling up the history of Swiss, or rather Swiss-German anti-tank rifles, one can see that they were not very useful as tank fighters, not even the most popular and widespread Solothurns. Nevertheless, an optical sight and large variety of ammunition available for the weapon (20x138 B or Lang Solothurn was used for German AA guns) the weapon was successfully used against lightly protected targets, serving in a way as a predecessor of modern anti-materiel rifles.

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