Finland's "Elephant Gun"

Many nations searched for effective anti-tank weapons in the interbellum years. One of the most popular countermeasures was the anti-tank rifle. These rifles ranging in caliber from 7.92 to 20 mm were issued to infantry units. Finland also followed this path as it nervously observed the development of armoured vehicles by its eastern neighbour, the Soviet Union.

Initially the Finns chose the 13.2 mm caliber, but doubts about its effectiveness crept in during development. The army decided to play it safe and develop a 20 mm anti-tank rifle, then make the final decision after comparative trials. In early 1939 the task of developing a 20 mm anti-tank rifle was given to the most famous Finnish arms designer, Aimo Johannes Lahti. By that time he had already designed the L-35 pistol and quite successful 20 mm aircraft autocannon. Lahti used his experience with the latter in designing a new anti-tank rifle.

Design

The anti-tank rifle used the 20x138B Solothurn cartridge used not only in anti-tank rifles made by that company, but in German Flak 30 and Flak 38 AA guns as well as the Italian Breda M/35.

The L-39 heavy anti-tank rifle was a semiautomatic gas operated rifle. The barrel was tapped for gas about two thirds of the way out, right behind the perforated barrel shroud. The gas tube is located under the barrel. It's equipped with a four-position valve to allow the mechanism to function in various atmospheric conditions and levels of barrel fouling. The barrel is equipped with a box type muzzle brake with five openings on each side. A tin casing is installed over the muzzle brake during travel. A perforated wooden shroud is installed over the barrel to make it easier to transport.

The receiver is rectangular in shape. A stock with a rubber pad is located on the rear. A wooden cheek rest is screwed in from the left. A pistol grip with a trigger is located underneath. The bolt handle is located on the right side of the receiver and the safety lever is on the left.

The anti-tank rifle is equipped with a folding bipod attached to the front of the receiver. There is also a mount with two wide and short skis. Iron sights are adjustable from 100 to 1400 meters. They are located to the left of the barrel axis, as a removable double-stack magazine fitting 10 rounds of ammunition is located in the center.

The ski mount is a distinctive feature of the Finnish anti-tank rifle.

L-39 anti-tank rifle in firing position.

L-39 anti-tank rifle crew in fighting near Viipuri (Vyborg). August 1941.

L-39 anti-tank rifle on an improved anti-aircraft mount. Ontojoki river, June 1944.

L-39/44 light AA rifle, vicinity of Kouvola, October 1944.

Finland made an attempt at modernizing the L-39/44 in the mid-1950s, altering the gas system to increase the rate of fire. The experimental 20 ltkiv/39–54L and 20 ltkiv/39–55/ST went through trials in 1956, but unsuccessfully. On one hand, the theoretical rate of fire indeed increased to 500 RPM, on the other hand the increased pressure limited the rifle's lifespan to about 250 shots. The ersatz AA guns also weighed 10 kg more than the initial gun. This was the end of development of 20 mm light AA guns in Finland.

The 20 pst.kiv. L-39/44 was not the first Finnish AA gun based on the L-39. Aimo Lahti developed an autocannon with a theoretical rate of fire of 700 RPM and a practical rate of fire of 250 RPM back in 1940. These guns were installed in pairs on a mount similar to the German Flak 30 and Flak 38. The weapon was accepted into service as the 20 ltk/40 VKT (also known as L-40 Vekontin). Finland used these weapons for training until the 1970s and maintained them as a part of a mobilization reserve into the 1980s.

The L-39 was only used to arm armoured vehicles once. One was installed into a Landsverk L-182 armoured car instead of a 13.2 mm L-35/36 machine gun.

2076 L-39 and L-39/44 anti-tank rifles were built in total. The first contract for 410 L-39 rifles was finished by June of 1941. 496 more were ordered in March and delivered by December. A new order for 1000 rifles was given in November of 1941. 946 of those were delivered by May of 1944. The last 54 of the batch were delivered as L-39/44 variants. Finally, another order for 170 rifles was made in July of 1944, all in the AA configuration. The Finnish army ended up with about 100 more L-39/44 rifles than produced new. An order was given in November of 1944 to convert 606 L-39 rifles into the AA variant, but only a small portion of the order had been completed by the time it was cancelled. These rifles remained in use until the 1960s, after which about 1000 rifles and 200,000 rounds of ammunition were sold to collectors, chiefly in the United States.

The Lahti L-39 (similar to other 20 mm anti-tank rifles, including the Swiss Solothurn and Japanese Type 97) was the result of wanting a "hand cannon" with high ballistics. The result was not as impressive as intended, as the 20 mm shell was no longer sufficient by 1940 to combat armoured vehicles and the rifle was way too heavy. It weighed 2.5-3 times as much as analogous weapons (the British Boys and Soviet PTRD/PTRS). However, since Finland had a shortage of anti-tank artillery, the L-39 was in demand throughout the entire war. The rifle's high precision allowed it to be used against small targets like vision slits and gun ports. It is also important to remember the conditions in which fighting took place on the Soviet-Finnish front. The 20 mm anti-tank rifle could be used effectively in the forests, but would not have been as effective in the open, where the gunner's position would be spotted long before his enemies entered effective range.

Tactical-technical data of the 20 mm 20 pst.kiv. L-39 anti-tank rifle.

Original article by Andrey Haruk.