In the summer of 1930, Sweden began testing a new 40-mm automatic gun, which was developed by Victor Hammar and Emmanuel Jansson, designers of the Bofors plant. No one then could predict such a long fate for this weapon.
The most widespread and used air defense system of the Second World War, actively used by both warring parties. In total, more than 100,000 installations of all types and modifications were produced in the world. In many countries, "Bofors" is still in service.
The assault rifle was produced in both land and ship versions with numerous modifications (casemate, towed, self-propelled armored and unarmored, railroad, airborne).
As of 1939 (at the time of the outbreak of hostilities in Europe), Swedish manufacturers exported Bofors to 18 countries of the world and signed licensing agreements with 10 more countries. The military industry of the Axis countries and the allies in the Anti-Hitler coalition was engaged in the release of guns.
Belgium became the first buyer of the land anti-aircraft gun. The first customer of the L60 naval anti-aircraft guns was the Dutch fleet, which installed 5 twin installations of this type on the light cruiser De Ruyter.
The number of countries that purchased Bofors L60 anti-aircraft guns at the end of the 30s included: Argentina, Belgium, China, Denmark, Egypt, Estonia, Finland, France, Greece, Norway, Latvia, Netherlands, Portugal, Great Britain, Thailand and Yugoslavia.
The Bofors L60 was produced under license in Belgium, Finland, France, Hungary, Norway, Poland and the UK. Bofors L60 was produced in very significant quantities in Canada and the USA. More than 100 thousand 40-mm Bofors anti-aircraft guns were manufactured all over the world by the end of World War II.
Anti-aircraft 40-mm guns produced in different countries have been adapted to local conditions of production and use. Components and parts of guns of different "nationalities" were often not interchangeable.
More than 5, 5 thousand Bofors were delivered under Lend-Lease to the USSR.
"Bofors" guarding the "Road of Life"
The automatic gun is based on the use of the recoil force according to the scheme with a short recoil of the barrel. All actions necessary for firing a shot (opening the bolt after a shot with extracting the sleeve, cocking the striker, feeding cartridges into the chamber, closing the bolt and releasing the striker) are performed automatically. Aiming, aiming of the gun and the supply of clips with cartridges to the store are carried out manually.
A high-explosive 900-gram projectile (40x311R) left the barrel at a speed of 850 m / s. The rate of fire is about 120 rds / min, which increased slightly when the gun did not have large elevation angles. This was due to the fact that gravity helped the ammunition supply mechanism. The projectile's own weight helped the reloading mechanism work.
The practical rate of fire was 80-100 rds / min. The shells were loaded with 4-round clips, which were inserted manually. The gun had a practical ceiling of about 3800 m, with a range of more than 7000 m.
The automatic cannon was equipped with an aiming system that was modern for those times. The horizontal and vertical gunners had reflex sights, the third member of the crew was behind them and worked with a mechanical computing device. The sight was powered by a 6V battery.
Despite the fact that Germany had its own 37-mm Rheinmetall anti-aircraft machine gun, the 40-mm Bofors L60 was actively used in the armed forces of Germany and its allies. The captured Bofors captured in Poland, Norway, Denmark and France were used by the Germans under the designation 4-cm / 56 Flak 28.
But the most massive copy of the Bofors L60 was the Soviet 37-mm automatic anti-aircraft gun mod. 1939 g. also known as 61-K.
After the failure of the attempt to launch into mass serial production at the plant near Moscow. Kalinin (No. 8) of the German 37-mm automatic anti-aircraft gun "Rheinmetall", due to the urgent need for such an anti-aircraft gun, it was decided at the highest level to create an anti-aircraft machine gun based on the Swedish system, which by that time had received worldwide recognition.
The gun was created under the leadership of M. N. Loginov and in 1939 it was put into service under the official designation “37-mm automatic anti-aircraft gun mod. 1939.
According to the leadership of the gun service, its main task was to combat air targets at ranges up to 4 km and at altitudes up to 3 km. If necessary, the cannon can also be used for firing at ground targets, including tanks and armored vehicles.
In terms of its ballistic characteristics, the 40-mm Bofors cannon was somewhat superior to the 61-K - it fired a slightly heavier projectile at a close muzzle velocity. In 1940, comparative tests of the Bofors and 61-K were carried out in the USSR, according to their results, the commission noted the approximate equivalence of the guns.
61-K during the Great Patriotic War were the main means of air defense of the Soviet troops in the front line. The tactical and technical characteristics of the gun allowed it to effectively fight the enemy front-line aviation, but until 1944 the troops experienced an acute shortage of automatic anti-aircraft guns. Only at the end of the war were our troops adequately covered from air strikes. On January 1, 1945, there were about 19,800 61-K and Bofors L60 guns.
After the end of World War II, the 37-mm 61-K and 40-mm Bofors L60 anti-aircraft guns took part in many armed conflicts, in a number of countries they are still in service today.
