During the Second World War, the American infantry quite successfully used the 60-mm M1 and M9 Bazooka rocket launchers against enemy tanks. However, this weapon, effective for its time, was not devoid of a number of disadvantages.
Based on combat experience, the military wanted more long-range, durable and less weather-affected weapons. During the hostilities, cases of loss of combat effectiveness of American grenade launchers, which had an electrical launch circuit after being exposed to rain, were repeatedly recorded.
In 1944, a light 57-mm dynamo-reactive (recoilless) gun M18 (in the American classification it was called "M18 recoillessrifle" - M18 recoilless gun) was adopted.
57 mm M18 recoilless gun
The M18 recoilless mechanism was a 1560 mm long steel rifled barrel open at both ends, in the rear part of which there is a folding bolt with a nozzle for the outlet of powder gases, compensating for the recoil when fired. On the barrel there is a pistol grip with a mechanical trigger mechanism, a folding two-legged bipod (in the folded position serves as a shoulder rest), as well as a standard optical sight bracket.
Ammunition for the M18 served as unitary shots with a steel sleeve. The mass of the shot was about 2.5 kg, of which about 450 grams fell on the powder - propellant charge and 1.2 kg - on the fired grenade. The steel sleeve had about 400 round holes in its side walls, through which most of the powder gases, when fired, broke through into the barrel chamber and back into the nozzle, thereby compensating for the recoil of the weapon and creating a significant danger zone behind the grenade launcher. The propellant propellant charge itself is inside the liner in a combustion bag made of nitrocellulose fabric. Ignition of the propellant charge is mechanical shock, using a standard primer-igniter located in the bottom of the sleeve. The shells are loaded into the grenade launcher from the breech after the bolt with the nozzle is folded back. After the shot, it was necessary to remove the spent cartridge case from the barrel.
With a mass of just over 20 kg, the 57-mm M18 was quite flexible in use and allowed shooting from the shoulder. However, the main position for shooting was firing from the ground (with an emphasis on the unfolded bipod).
The most accurate shooting was achieved when the body of the recoilless gun was mounted on the tripod of the Browning M1917A1 machine gun. The effective range of fire was within 400 m, the maximum range exceeded 4000 m.
The first use of the M18 anti-tank recoilless vehicles dates back to 1945; they were also massively used during the Korean War. At the same time, they showed insufficient effectiveness against Soviet medium tanks T-34, with armor penetration of 75-mm armor-piercing damaging effect of cumulative shells was not always sufficient. However, they were successfully used by the American and South Korean infantry against light fortifications, machine-gun nests and other similar targets, thanks to the presence of high-explosive fragmentation and incendiary smoke shots in the ammunition load.
Having a relatively small mass, the M18 could be carried and used by one serviceman, for which it was valued among the troops. This weapon, in fact, was a transitional model between hand-held anti-tank grenade launchers (RPGs) and recoilless guns. Along with the Bazooka grenade launchers and anti-tank rifle grenades, recoilless 57-mm guns in the first post-war decade were the main anti-tank weapons of the company link in the American army.
In the United States, the 57-mm M18 recoilless systems were quickly replaced by more powerful grenade launchers and recoilless guns, however, as part of the program of military assistance to US-friendly regimes, it spread widely throughout the world. In some countries, licensed production of these non-rollbacks has been established. In Brazil, the M18 was produced until the mid-80s. The Chinese version of this weapon, known as the Type 36, was used extensively in the Vietnam War, this time against the Americans and their satellites.
In June 1945, the 75-mm M20 recoilless gun was adopted. By its design, the M20 in many ways resembled the 57 mm M18, but it was the largest and weighed 52 kg.
There was a wide range of ammunition for it, including a cumulative projectile with armor penetration up to 100 mm, a fragmentation projectile, a smoke projectile and buckshot. An interesting feature of the M20 ammunition was that the shells had ready-made rifling on the leading belts, which, when loaded, were combined with the rifling of the gun barrel.
The effective range of firing at tanks did not exceed 500 m, the maximum firing range of a high-explosive fragmentation projectile reached 6500 m.
Unlike the 57-mm M18 gun, firing was provided only from the machine. As the latter, the machine gun from the Browning M1917A1 machine gun of 7.62 mm caliber was most often used.
In addition to the easel version, this gun was installed on various vehicles: cross-country vehicles, armored vehicles, armored personnel carriers, and even scooters.
Armored car Ferret MK2 with a 75-mm recoilless gun
Scooter Vespa with 75-mm recoilless gun M-20
The 75-mm M20 recoilless gun in the infantry units of the American army was an anti-tank weapon of the battalion level. At the final stage of the war, the M20 was limitedly used against Japanese firing points during the battles in Okinawa. It was used on a much larger scale during the hostilities in Korea.
North Korean tank T-34-85 knocked out at Daejeon
Although the armor penetration of the 75-mm HEAT shells was quite enough to confidently defeat the North Korean thirty-fours, this weapon was not particularly popular as an anti-tank weapon.
The reason for this was the large unmasking effect when firing, the need for a certain free space behind the gun, which made it difficult to place it in shelters, the low rate of fire and significant weight, which prevents a quick change of positions.
Much more often in the mountainous and hilly terrain characteristic of a significant part of the Korean Peninsula, the M20 was used to fire at enemy positions and destroy enemy firing points.
The 75 mm M20 recoilless gun has become widespread. The guns can still be found in the arsenals of a number of Third World countries. Chinese copies of the Type 52 and Type 56 were first used by the Viet Cong against the Americans, and then by the Afghan mujahideen against the Soviet contingent in Afghanistan.
Chinese 75-mm recoilless guns Type 56 and Type 52
After the start of mass production in the USSR of the T-54 and IS-3 tanks, the 75-mm M20 recoilless gun lost its relevance as an anti-tank weapon. In this regard, work began in the United States to create more powerful recoilless guns.
The haste in this matter did not lead to anything good. The 105 mm M27 recoilless gun, which was put into service in 1951, was unsuccessful. In 1953, it was replaced by the 106mm M40 (which was actually 105mm in caliber, but marked to avoid confusion with the previous model).
M40 recoilless gun in firing position
The M40 is the first recoilless gun adopted for service in the United States, equipped with a sighting device for firing both direct fire and from closed firing positions. For this, the corresponding sights are installed on the gun.
Like other American recoilless guns, a perforated sleeve with small holes was used here. Some of the gases passed through them and were thrown back through special nozzles in the breech of the barrel, thus creating a reactive moment damping the recoil force.
The rotary and lifting mechanisms of the implement are equipped with manual drives. The carriage is equipped with three sliding beds, one of which is equipped with a wheel, and the other two are equipped with folding handles. For zeroing, a 12.7 mm M8 sighting machine gun is installed on top of the gun (which uses special tracer cartridges with ballistics for firing, corresponding to the trajectory of a 106 mm cumulative projectile).
The maximum firing range of 18, 25 kg with a high-explosive fragmentation projectile reached 6800 m. The firing range of an anti-tank cumulative projectile was 1350 m (effective about 900 m). Rate of fire up to 5 shots / min.
The ammunition load included shells of various purposes: high-explosive fragmentation, fragmentation with ready-made lethal elements, cumulative, incendiary and armor-piercing high-explosive with plastic explosives. Penetration of the first HEAT shells was within 350 mm.
Taking into account the total length of 3404 mm and the mass of the 209 kg gun, the M40 gun was installed on various vehicles much more often compared to earlier American recoilless vehicles. Most often these were light off-road vehicles.
BTR М113 with mounted recoilless gun М40
However, there were repeated attempts to mount 106-mm recoilless guns on heavier equipment. The most famous combat vehicle was the American M50 self-propelled anti-tank gun, also known as the Ontos. Which was created on the basis of the experienced T55 armored personnel carrier in 1953 and was intended to arm the marines and airborne forces.
PT ACS "Ontos"
The self-propelled gun was armed with six M40A1C recoilless guns, placed outside on the sides of the turret, four 12.7 mm sighting guns and one 7.62 mm anti-aircraft machine guns.
During serial production in 1957-1959, 297 M50s were produced, they were in service with the US Marine Corps from 1956 to 1969 and took part in the Vietnam War. Basically "Ontos" were used as a means of artillery support for the infantry. Their light weight made it easy to maneuver on the marshy soils of Vietnam. At the same time, "Ontos" with their bulletproof armor were very vulnerable to RPGs.
Another mass-produced vehicle with 106-mm recoilless guns was the Japanese Type 60 self-propelled artillery unit. The main armament of the self-propelled artillery is two modified American M40 recoilless guns, which are mounted openly on a rotating platform and shifted to the right of the centerline of the hull. For zeroing, 12.7 mm M8 machine guns are used. The crew is two people: the driver and the vehicle commander, who simultaneously acts as a gunner. The standard ammunition load is six rounds.
Japanese self-propelled artillery unit Type 60
Serial production of Type 60 was carried out by Komatsu from 1960 to 1979, a total of 223 machines were produced. As of 2007, these tank destroyers were still in service with the Japan Self-Defense Forces.
The 106-mm M40 recoilless guns in the American army were replaced by ATGMs in the mid-70s. In the armies of many other states, these widespread weapons continue to be used to this day. In some countries, licensed production of 106-mm recoilless wheels and ammunition has been established.
In the course of hostilities, it was relatively rare to fire at M40 recoilless tanks, usually they were used to provide fire support, destroy firing points and destroy fortifications. For these purposes, simple and reliable in use, with a sufficiently powerful projectile, the guns were the best fit.
106-mm recoilless guns are very popular among various insurgents. It has become a common practice to make handicraft installations on cars that were not originally intended for this.
106-mm M40 recoilless gun on Mitsubishi L200 pickup
In the United States and Canada, after the armed forces finally abandoned recoilless weapons, their service continued with the Avalanche Security Service.
The guns were installed both on pre-equipped platforms and on tracked conveyors.
The American “nuclear recoilless” deserves special mention: the 120-mm M28 gun and the 155-mm M29 gun.
120-mm gun М28
Both guns fired the same XM-388 Davy Crocket projectile with a W-54Y1 nuclear warhead with a yield of 0.01 kt. The over-caliber drop-shaped projectile was attached to the piston, which was inserted into the barrel from the muzzle and separated after the shot. It was stabilized in flight by the tail unit.
Under the barrel of the guns, a sighting barrel of 20 mm caliber for the M28 and 37 mm for the M29 was fixed. The light M28 gun was mounted on a tripod and, when carried manually on the battlefield, was quickly disassembled into 3 parts, the weight of which did not exceed 18 kg.
155-mm gun М29
The M29 gun was installed in the back of an all-wheel drive vehicle on a pedestal carriage. The same car carried 6 shots and a tripod from which it was possible to fire from the ground. The firing range was not great, up to 2 km for the M28 and up to 4 km for the M29. The maximum circular probable deviation (CEP) is 288 m and 340 m, respectively.
The Davy Crockett system has been in service with American units in Europe since the mid-60s. In the late 70s, the system was removed from service.
Work on recoilless guns in Great Britain began after the end of World War II. Taking into account the American experience, the British decided to immediately build guns capable of effectively fighting Soviet post-war tanks.
The first British model was the 120-mm recoilless gun "BAT" (L1 BAT), which entered service in the mid-1950s. It resembles a conventional artillery gun with a lightweight wheeled carriage with a large shield cover and had a rifled barrel with a bolt, into the rear end of which a nozzle is screwed. A tray is fixed on top of the nozzle for convenient loading. On the muzzle of the barrel there is a special device for towing the gun by a car or tracked tractor.
Shooting is carried out with unitary loading shots with armor-piercing high-explosive tracer shells filled with a plastic explosive with armor penetration of 250-300 mm. The shot length is about 1 m, the projectile weight is 12, 84 kg, the effective firing range at armored targets is 1000 m.
120-mm recoilless gun "BAT" in the firing position
The use by the British of high-explosive armor-piercing shells with plastic explosives was due to the desire to have a single universal shell in the ammunition load of the gun, which could fire at any targets, depending on the installation of the fuse.
120-mm shells "BAT"
When hitting the armor, the soft head of such a projectile flattens, the explosive sticks to the armor, and at this moment is blown up by the detonator. In the armor, stress waves arise, leading to the separation of fragments from its inner surface, flying at a tremendous speed, striking the crew and equipment.
In addition to the disadvantages inherent in all recoilless guns (small effective firing range, low accuracy when firing at maneuvering targets, the presence of a dangerous zone behind the gun due to the outflow of powder gases during firing), the BAT also has the disadvantage of conventional guns - a large weight (about 1000 kg) …
The 120-mm recoilless gun "Bat" later went through several stages of modernization, in accordance with which its name was changed to "Mobat" (L4 MOBAT).
"Mobat" was a lightweight version of the artillery system. The weight reduction by about 300 kg was achieved mainly due to the dismantling of the shield cover. A sighting machine gun was installed above the barrel.
British 120-mm recoilless gun "Mobat"
Further modernization led to the creation in 1962 of an almost new weapon "VOMBAT" (L6 Wombat). It has a rifled barrel made of high-strength steel with an improved bolt. The gun carriage is made of light alloys. At the firing position, the carriage is held in an upright position by means of a forward-leaning boom. On top, parallel to the barrel, a sighting 12, 7-mm machine gun is installed. The weight of the gun is about 300 kg.
British 120-mm recoilless gun "Wombat"
The ammunition includes unitary rounds with a cumulative projectile weighing 12, 84 kg, penetrating at a distance of 1000 m armor thickness of 250-300 mm, an armor-piercing tracer projectile with a plastic explosive, as well as a fragmentation projectile with arrow-shaped striking elements.
120-mm recoilless gun "Wombat" on the car "Land Rover"
During the development of the modernized model, great attention was paid to ensuring convenience and safety when firing and maintaining the gun. To increase mobility, the Wombat cannon can be mounted on the FV 432 Trojan armored personnel carrier or Land Rover vehicle.
120-mm recoilless gun "VOMBAT" on the armored personnel carrier FV 432 "Trojan"
The recoilless guns served in the British army much longer than in the American, remaining in service until the end of the 80s. In some armies of the countries of the British Commonwealth, 120-mm recoilless guns are still in service.
Created as an easy and inexpensive means of fighting Soviet tanks, American and British recoilless guns in the early 70s were pushed aside from this role by more effective guided anti-tank missiles.
Nevertheless, recoilless guns have become widespread throughout the world, few armed conflicts have gone without their participation. Considerably inferior to ATGMs in firing accuracy, recoilless guns unconditionally win in the cost of ammunition, durability and flexibility of use.