During the Great Patriotic War, small-caliber anti-aircraft artillery and anti-aircraft machine-gun installations were the main means of enemy air defense in the front-line zone. It was from the fire of the MZA and ZPU that Soviet attack aircraft and close-range bombers suffered the main losses during air strikes on positions and concentrations of German troops, transport hubs and columns on the march. Moreover, in the second half of the war, after the Luftwaffe lost air superiority, the role of rapid-fire anti-aircraft guns only increased. Pilots of Soviet attack aircraft and dive bombers noted that the destructive fire of German small-caliber anti-aircraft guns remained very dense until the surrender of the German troops.
In the first part of the review, we will talk about German anti-aircraft machine gun mounts of rifle caliber. Although the Soviet Il-2 attack aircraft was hardly vulnerable to small arms bullets, in 1941 the Red Army Air Force assault regiments had a significant number of obsolete aircraft: I-15bis, I-153 fighters and R-5 and R-Z light bombers. On these vehicles, all reservations, at best, were represented only by the pilot's armored backrest, and the gas tanks were not protected or filled with neutral gas. In addition, the fire of German 7, 92-mm anti-aircraft guns posed a danger not only for improvised attack aircraft, but also for front-line bombers: Su-2, Yak-2, Yak-4, SB-2, Ar-2, Pe-2 - which often operated at low altitude. In the initial period of the war, the Soviet command was compelled to engage fighter aircraft for assault operations against the advancing German troops. If the fighters of the old types with air-cooled engines I-15bis, I-16 and I-153 had good protection in front, then the more modern MiG-3, Yak-1 and LaGG-3 with liquid-cooled engines were quite vulnerable even to a single shot of water radiator. In addition, it is reliably known that the command of the Red Army in 1941 in the daytime sent long-range bombers DB-3, Il-4 and Er-2 for strikes on the Wehrmacht columns. In order to accurately cover enemy manpower, vehicles and military equipment with bombs, the bombers had to descend to a height of several hundred meters, falling into the zone of effective fire of anti-aircraft machine guns. Thus, in the initial period of the war, ZPUs in the German army played an important role in providing protection against low-altitude bombing and assault strikes by Soviet aviation.
Most often, for firing from German rifles and machine guns during the Second World War, the cartridge 7, 92 × 57 mm was used with the Ss bullet (German Schweres spitzgeschoß - pointed heavy) weighing 12, 8 g. It left the 700 mm barrel at a speed of 760 m / with. For firing from anti-aircraft 7, 92-mm machine guns, the Germans very widely used cartridges with armor-piercing bullets S.m. K. (German Spitzgeschoß mit Kern - pointed with a core). At a distance of 100 m, this bullet weighing 11.5 g with an initial speed of 785 m / s along the normal could penetrate 12 mm armor. The ammunition load of anti-aircraft machine guns could also include cartridges with P.m. K. armor-piercing incendiary bullets. - (German Phosphor mit Kern - phosphoric with a core). The armor-piercing incendiary bullet weighed 10 g and had an initial velocity of 800 m / s.
To adjust anti-aircraft fire, a cartridge with an S.m. K. armor-piercing tracer bullet was loaded into the machine-gun belt every 3-5 conventional or armor-piercing cartridges. L'spur - (German Spitzgeschoß mit Kern Leuchtspur - pointed tracer with a core). An armor-piercing tracer bullet weighing 10 g accelerated in the barrel to 800 m / s. Its tracer burned at a range of up to 1000 m, which exceeded the effective range of fire on air targets for weapons of 7.92 mm caliber. In addition to adjusting and targeting, the armor-piercing tracer cartridge could ignite fuel vapor when it broke through the wall of the gas tank.
Let's start the story about German anti-aircraft machine guns of rifle caliber with MG.08, which was the German version of the Hiram Maxim system. This weapon was actively used by the German army during the First World War, including for firing at air targets. In the first half of the 30s, as part of the program for improving machine gun armament initiated by the Reichswehr Arms Directorate, the machine gun was modernized.
As a result of the modernization, the MG.08, used for air defense purposes, received an anti-aircraft sight, a sliding anti-aircraft tripod and a shoulder rest, the rate of fire was increased to 650 rds / min. However, the mass of the machine gun in a combat position exceeded 60 kg, which did not contribute to its mobility. For this reason, during the Second World War, MG.08 machine guns were mainly used for anti-aircraft cover of rear units.
Most often, German anti-aircraft Maxims were installed on stationary positions or various transport mobile platforms: horse-drawn carts, cars and railway cars. Although by the beginning of World War II, this water-cooled machine gun was considered outdated, its reliable, albeit somewhat heavyweight design and the ability to conduct intense fire without the risk of overheating the barrel allowed it to remain in service. Anti-aircraft machine guns MG.08 were in reserve and guard units, as well as on stationary installations in fortified areas until the end of hostilities. When the crew did not need to move the weapon on them, the outdated water-cooled machine gun performed very well. In terms of the density of fire, it was not inferior to other, more modern machine guns. Moreover, the MG.08 could fire longer than the newer air-cooled samples without the risk of overheating the barrel.
Due to the heavy weight, the mobility of the MG.08 did not meet modern requirements, and in the early 30s in Germany, several promising infantry machine guns were created that were more consistent with the military's ideas about the weapons of mobile warfare. The first model, which was put into service in 1931, was the MG.13 light machine gun, developed using the MG.08 automation scheme. The specialists of Rheinmetall-Borsig AG tried to make the weapon as light as possible. At the same time, there was a refusal from the water cooling of the barrel and from the tape supply. The barrel on the MG.13 is now removable. The machine gun used drums for 75 rounds, or a box magazine for 25 rounds. The mass of the unloaded weapon was 13.3 kg, the rate of fire was up to 600 rds / min. To reduce the size of the tubular butt with a folding shoulder rest folded to the right. Simultaneously with the sector sight on the MG.13, it was possible to install an anti-aircraft ring sight.
Despite the advantage of the MG.13 over the outdated standard light machine gun of the Reichswehr MG.08 / 15, it had many disadvantages: the complexity of the design, the lengthy barrel change and the high cost of production. In addition, the military was not satisfied with the store power system, which increased the weight of the carried ammunition and reduced the combat rate of fire, which made the machine gun ineffective when firing intensively from the machine.
Therefore MG.13 was released relatively little, serial production continued until the end of 1934. Nevertheless, MG.13 machine guns were in the Wehrmacht during the initial period of the war. For anti-aircraft fire, the MG.13 could be mounted on the MG.34 machine gun.
In 1934, the MG.34 machine gun, which is often called the "first single", entered service. He quickly gained popularity in the Wehrmacht and strongly pushed other samples. The MG.34, created by Rheinmetall-Borsig AG, embodied the concept of a universal machine gun developed on the basis of the experience of the First World War, which could be used as a manual one when firing from a bipod, as well as an easel from an infantry or anti-aircraft machine. From the very beginning, it was envisaged that the MG.34 machine gun would also be installed on armored vehicles and tanks, both in ball mounts and on various turrets. This unification simplified the supply and training of troops, and ensured high tactical flexibility.
The MG.34 installed on the machine was powered by ribbons from a box for 150 rounds or 300 rounds. In the manual version, compact cylindrical boxes for 50 rounds were used. In 1938, a magazine-fed modification was adopted for anti-aircraft installations: for machine guns, the cover of the box with a tape drive mechanism was replaced with a cover with a mount for a 75-cartridge coaxial drum magazine, structurally similar to the magazines of the MG.13 light machine gun and the MG.15 aircraft machine gun. The store consisted of two connected drums, the cartridges from which are fed alternately. The advantage of the store with alternate supply of cartridges from each drum, in addition to the relatively large capacity, was considered to be the preservation of the balance of the machine gun as the cartridges were consumed. Although the rate of fire when powered from a drum magazine was higher, this option did not take root in anti-aircraft installations. Most often, belt-fed machine guns from a cylindrical 50-cartridge box were used to fire at aircraft. Drum magazines were not popular due to their high sensitivity to pollution and the complexity of the equipment.
MG.34 had a length of 1219 mm and in the manual version without cartridges weighed a little more than 12 kg. Machine guns of the first series gave a rate of fire of 800-900 rds / min. However, based on combat experience, due to the use of a smaller shutter mass, the rate was increased to 1200 rds / min. In case of overheating, the barrel could be quickly replaced. The barrel was supposed to be changed every 250 shots. For this, the kit included two spare barrels and an asbestos mitten.
For shooting at air targets, the MG.34 was mounted on a Dreiben 34 tripod and was equipped with anti-aircraft sights. The standard machine also allowed for the possibility of anti-aircraft fire using the special Lafettenaufsatzstück anti-aircraft rack, albeit with less convenience.
The advantages of a single ZPU using MG.34 were: simplicity of design, relatively low weight and the ability to mount a conventional light machine gun taken from a line unit. These qualities were especially appreciated at the front line, since it was difficult to place more bulky anti-aircraft guns in the trenches.
Soon after the start of mass production of the MG.34, the German command was puzzled by the need for anti-aircraft cover for troops on the march. For this, the MG-Wagen 34 cartwagon was originally used with a pivot installation and a box for ammunition boxes installed on it. The crew of the "anti-aircraft self-propelled gun" consisted of a driver (aka the second number of the machine-gun crew) and a gunner. However, this option did not receive much distribution, since the calculation was in cramped conditions, and fire on the move was impossible.
In 1936, the troops began to receive the MG-Wagen 36 "cart" with twin Zwillingssockel 36 installations. According to the reference data, the machine gun could fire at air targets at a range of up to 1800 m. In fact, the effective firing range at air targets did not exceed 800 m, the ceiling was 500 m. The machine with the gunner's seat and frame was mounted on a pedestal support, two machine guns were attached to the frame, cartridge boxes with strips for 150 rounds and control handles. The machine guns had a single descent, a ring anti-aircraft sight was located on the bracket. The combat rate of fire in short bursts was 240-300 rds / min, and in long bursts - up to 800 rds / min.
The MG-Wagen 36 wagon itself was a single-axle trailed vehicle specially designed for a mobile ZPU. Its main components - an axle with two wheels, a body and a drawbar were manufactured using "automotive" technologies. The open body of riveted sheet steel is similar to the side platform of a small pickup truck. The axle had no suspension, but was rigidly attached to the body. Wheels - automobile, from a light truck. The hubs are equipped with mechanically driven drum brakes.
In the parking lot, the stability of the carriage on two wheels is ensured by two folding racks located at the front and rear of the body. A drawbar with a towing hitch made it possible to hook the cart to the front of the gun, which was harnessed to a pair of horses.
An important advantage of the MG-Wagen 36 was its constant readiness for battle while on the move. However, it soon became clear that horses in most cases are very frightened by aircraft flying at low altitude, and shelling and bombing from the air generally make them uncontrollable, which of course greatly reduced the effectiveness of the horse-drawn anti-aircraft machine gun mount. In this regard, a towed carriage with a machine-gun twin was often attached to various vehicles with an internal combustion engine, for example, to the Sd. Kfz.2 half-track motorcycle. Towed vehicles MG-Wagen 36 on the Eastern Front met until mid-1942. A number of ZPU Zwillingssockel 36 were installed on trucks, railway platforms and armored vehicles.
In addition to single and twin anti-aircraft machine gun mounts, the Germans built a small number of quadruple ZPUs. In the case of using the MG.34 late versions, the total rate of fire in this case was 4800 rds / min - twice as much as that of the Soviet quadruple 7, 62-mm anti-aircraft machine gun M4 mod. 1931, which used four Maxim machine guns arr. 1910/30 Since the MG.34 machine guns were air-cooled, the mass of the German installation was about 2.5 times less.
However, in Germany during the war years, attempts were made to create real 16-barreled monsters, which, given the total shortage of machine-gun armament in the second half of the war, was an impermissible waste for Germany.
For all its merits, the MG.34 was difficult and expensive to manufacture. In addition, during the hostilities on the Eastern Front, it turned out that the machine gun is very sensitive to the wear of parts and the state of the lubricant, and highly qualified machine gunners are required for its competent maintenance. Even before the launch of MG.34 into mass production, the Infantry Weapons Department of the Land Force Armaments Directorate drew attention to its high cost and complex design. In 1938, the firm Metall-und Lackwarenfabrik Johannes Großfuß presented its own version of the machine gun, which, like the MG.34, had a short barrel stroke with locking rollers with lateral expansion. But unlike the MG.34, stamping and spot welding were widely used in the new machine gun. As in the MG.34 machine gun, the problem of barrel overheating during prolonged firing was solved by replacing it. The development of the new machine gun continued until 1941. After comparative tests with the improved MG.34 / 41, it was adopted in 1942 under the designation MG.42. Compared to MG.34, the cost of MG.42 has decreased by about 30%. The production of MG.34 took approximately 49 kg of metal and 150 man-hours, for MG.42 - 27, 5 kg and 75 man-hours. Machine guns MG.42 were produced until the end of April 1945, the total production at the enterprises of the Third Reich amounted to more than 420,000 units. At the same time, the MG.34, despite its shortcomings, was produced in parallel, albeit in smaller quantities.
The MG.42 machine gun had the same length as the MG.34 - 1200 mm, but was slightly lighter - without cartridges 11, 57 kg. Depending on the mass of the shutter, its rate of fire was 1000-1500 rds / min. Due to its higher rate of fire, the MG.42 was even more suitable for anti-aircraft fire than the MG.34. However, by the beginning of the mass production of MG.42, it became clear that the role of a rifle-caliber ZPU in the air defense system had sharply decreased due to the increased security and flight speed of combat aircraft. For this reason, the number of specialized anti-aircraft installations in which the MG.42 was used was relatively small. At the same time, MG.42 machine guns were widely used in universal turrets on armored personnel carriers and tanks.
MG.34 and especially MG.42 are rightfully considered one of the best machine guns used during the Second World War. In the post-war period, these weapons have spread widely throughout the world and have been actively used in regional conflicts. Modifications of MG.42 for other cartridges and with bolts of various weights were mass-produced in different countries and, in addition to the infantry options on the bipod and the machine, they can often still be found mounted on anti-aircraft turrets as part of the armament of various armored vehicles.
At the end of the part devoted to anti-aircraft machine gun installations of rifle caliber, developed and produced in Germany, let's try to assess how effective they were. As already mentioned, the Soviet Air Force used both armored attack aircraft and fighters and light bombers uncovered by armored protection to inflict bombing and assault strikes on the positions and transport columns of the Nazis.
On the Il-2 attack aircraft, the engine, cockpit and fuel tanks were covered with a streamlined armored body and armored partitions with a thickness of 4 to 12 mm. The steel armor included in the aircraft's power set was supplemented with multilayer bulletproof glass. The canopy of the lantern was made of 64 mm glass. The windshield withstood the shelling of 7, 92-mm armor-piercing bullets fired at point-blank range. The armor protection of the cockpit and engine, due to the significant angles of encounter with the armor, in most cases did not penetrate with armor-piercing rifle caliber bullets. Often, attack aircraft returned from a combat sortie, having dozens, and sometimes hundreds of holes from bullets and fragments of anti-aircraft shells. According to the Russian historian O. V. Rastrenin, during the fighting, 52% of the Il-2's hits were on the wing and the unarmored part behind the cockpit, 20% of the damage related to the fuselage as a whole. The engine and hoods received 4% damage, the radiators, cab and rear gas tank received 3% damage each.
However, this statistic has a significant flaw. It is safe to say that there were more IL-2s shot down due to hitting critical parts: the engine, cockpit, gas tanks and radiators. In most cases, experts who surveyed aircraft that received combat damage did not have the opportunity to inspect attack aircraft struck by anti-aircraft fire in the target area. It is known that during the Great Patriotic War, about half of the patients in Soviet hospitals were wounded in the limbs. But this does not mean that the bullets do not hit the head and chest. This is evidence that those who received bullet wounds to the head and chest, in most cases, die on the spot. Therefore, it is a mistake to draw conclusions only on the basis of damage to the returned aircraft. The planes and fuselage riddled with bullets and shrapnel do not need additional protection measures. Their strength was enough to continue the flight even with extensive damage to the skin and power set.
But in any case, it can be argued that the Il-2 was sufficiently protected from small arms fire. Armor 7, 92-mm bullets, as a rule, did not penetrate, and their destructive effect on the structural elements of the attack aircraft with single hits turned out to be insignificant. But at the same time, it would be wrong to say that rifle-caliber ZPUs were absolutely powerless against armored attack aircraft. A dense burst of a rapid-fire machine gun could well have inflicted damage that impeded the fulfillment of a combat mission. In addition, on two-seater vehicles, the gunner's cabin was not covered at all by armor from below and from the side. Many authors writing about the combat use of the Il-2 overlook the fact that in the depths of the enemy defense, Soviet attack aircraft had to fly at low altitudes, bypassing areas with a high concentration of anti-aircraft artillery, avoiding encounters with enemy fighters. At the same time, a long flight with closed armored shutters of the oil cooler was impossible. According to the recollections of test pilot and cosmonaut Georgy Timofeevich Beregovoy, who flew during the war on the Il-2 and received the first hero star in 1944, he made an emergency landing in the forest, after he fired a machine-gun burst into an oil cooler while leaving the target. In addition, pilots, especially young ones, often forgot to close the oil cooler flaps over the target.
As for fighters and non-armored close-range bombers, their survivability when fired from 7, 92-mm machine guns strongly depended on the type of power plant used. Air-cooled engines were much less vulnerable to combat damage than liquid-cooled engines. Apart from better combat survivability, the radial drive is much shorter and presents a smaller target. The combat aircraft that entered service on the eve of the war, for the most part, had a system for filling the tanks with neutral gas, which excluded the explosion of fuel vapor when an incendiary bullet hit. In the second half of the war, the gas tanks of fighters, as a rule, had protection against fuel leaks during shooting. Since the floor and side walls of the cockpit of Soviet fighters and front-line bombers were not armored, 7.92 mm bullets posed a serious danger to pilots. But much depended on the tactics used by Soviet pilots when attacking ground targets. As you know, most of the aircraft went astray during repeated approaches to the target, when the German anti-aircraft crews managed to react and take aim. Rifle-caliber ZPUs were relatively ineffective against the Pe-2 and Tu-2 bombers, which carried out dive bombing. The entry of the aircraft at the peak began from a height inaccessible to the fire of 7, 92-mm anti-aircraft guns, and on the combat course until the moment of bombing, due to the high speed and stress experienced by the shooters, it was very difficult to get into the dive bomber. And after the separation of the bombs, anti-aircraft gunners often did not have time to conduct aimed fire at aircraft.
Due to the availability of the rifle-caliber machine guns themselves and ammunition for them, these weapons were used until the last hours of the war for firing at air targets. Single and paired 7, 92-mm ZPU in comparison with larger anti-aircraft guns had a smaller weight and dimensions. The flip side of using relatively low-power and cheap 7, 92-mm rounds was a small effective firing range at air targets and a low damaging effect. So, in order to shoot down a Yak-7b fighter, on average 2-3 20-mm projectiles or 12-15 7, 92-mm bullets had to hit it.
