M18 recoilless rifle | |
---|---|
M18 on a M1917A1 Tripod | |
Type | Recoilless anti-tank weapon |
Place of origin | United States |
Service history | |
In service | 1945–1960s |
Used by | See users |
Wars | |
Production history | |
Designer | Kroger and Musser |
Designed | 1942 |
Produced | October 1944 |
Variants | Type 36 |
Specifications | |
Mass | 44.4 lb (20.1 kg) [2] |
Length | 61.6 in (1,560 mm) [2] |
Crew | 1 or 2 |
Shell | |
Caliber | 57 mm (2.2 inches) |
Action | Interrupted lug rotating breechblock [2] |
Recoil | Recoilless |
Carriage | M1917A1 machine gun tripod mount |
Elevation | +65° to −27° |
Traverse | 360° |
Muzzle velocity | 1,200 ft/s (370 m/s) [2] |
Effective firing range | 490 yd (450 m) |
Maximum firing range | 4,340 yd (3.97 km) [2] |
Sights | Telescope M86C 2.8-power [4] |
The M18 recoilless rifle is a 57 mm shoulder-fired, anti-tank recoilless rifle that was used by the U.S. Army in World War II and the Korean War. Recoilless rifles are capable of firing artillery-type shells at reduced velocities comparable to those of standard cannon, but with greater accuracy than anti-tank weapons that used unguided rockets, and almost entirely without recoil. The M18 was a breech-loaded, single-shot, man-portable, crew-served weapon. It could be used in both anti-tank and anti-personnel roles. The weapon could be both shoulder fired or fired from a prone position. The T3 front grip doubled as an adjustable monopod and the two-piece padded T3 shoulder cradle could swing down and to the rear as a bipod for the gunner. The most stable firing position was from the tripod developed for the water-cooled Browning M1917 machine gun. [5]
During World War II, the U.S. Army's Artillery Section was working on a 105 mm recoilless cannon, based on captured models of the German 10.5 cm Leichtgeschütz 40 that used a plastic blow out plug in the cartridge case. At the same time, there was a freelance research by the U.S. Army's Infantry Section of a man-portable recoilless 57 mm cannon by two engineers, named Kroger and Musser. Instead of a blowout plug, the infantry section's recoilless cannon used a British development, Ordnance, RCL, 3.45 in developed by Dennistoun Burney, from in which the cartridge case had hundreds of small holes in the side walls with a lining of plastic on the inside of the cartridge case walls to keep water and other elements out until the round was fired. Another unique innovation was the use of pre-engraving bands on the 57 mm projectile that engaged the barrel's rifling. [note 1] The belief was this feature would reduce friction on firing, allowing more of the propellant gases to be used to force the shell towards the target and less being used to achieve the recoilless effect and therefore giving their design a much higher muzzle velocity than most recoilless cannon at that time period had achieved. [6] [note 2]
The "Kromuskit", as the new 57 mm weapon was called (a word play on the engineers' family names) was officially designated the T15 and first tested in November 1943. The tests proved that the Infantry Section's concept for a recoilless weapon was superior to the Artillery Section's concept and the development of the 105 mm weapon was canceled. [7] In late 1944, the T15 was redesignated the M18 57 mm recoilless. The cannon and 57 mm ammunition were placed in mass production. Four types of ammunition were initially produced: [note 3] an anti-tank HEAT round (T20E2 / M307), an HE round (T22 / M306), a Smoke (White Phosphorus) "bursting smoke" round (T23 / M308), and a Training Practice round. [8] By early 1945, over 2,000 M18 recoilless rifles and 800,000 rounds of ammunition were on order. [6] After World War II ended, a canister round (T25E5) with a range of 175 meters was also produced.
The weapon was crewed by a two-man team, the gunner and the loader, who fired it from either a prone, kneeling, or standing position. It could also be awkwardly carried, fired from the shoulder and reloaded by one man in an emergency, fired prone from the extended T3 monopod and bipod, or fired from a fixed position on a cradle mounted on the M1917A1 machine gun tripod. The weapon was carried in a T27 Cover with two padded shoulder straps, designed to be simultaneously carried by two men in line with the straps slung over their shoulder on one side.
Ammunition was packed four shells to a wooden crate, each crate weighing about 40 lbs and had a volume of 0.86 cubic feet. Three 57 mm recoilless rifle shells could be carried per M6 rocket bag (designed for the 2.36-in bazooka rockets) and slung on one shoulder by the ammunition bearers assigned to the weapon.
The first fifty [9] production M18 57 mm cannons and ammunition were rushed from the factories to the European theater in March 1945. Further examples were subsequently sent to the Pacific Theater. The first combat the new cannon saw was with the U.S. Army's 17th Airborne Division near Essen, Germany as well as U.S. Forces in the Po Valley in Italy during the 1945 Spring Offensive. While the performance of the high explosive (HE) warhead was impressive, the M18's 57 mm HEAT round was slightly less so, only about 76.2 mm (3 in) of armor penetration at 90 degrees, [10] [11] compared with the M6A3 rocket for the Bazooka which had a penetration of 100 mm.[ citation needed ] The only effective way to knock out German tanks was a clean shot to the rear of the tank or to cause malfunctions by hits on the seams or joint of the tanks such as the gun turret elevation joint of the main gun, junction points of the turret and hull which would cause burn over of working mechanism and produce jamming and finally a hit on the tracks to immobilize a tank. They could then be destroyed by infantry Bazooka team, anti-tank guns or field artillery. [12] [13] [note 4]
In the Pacific Theater, the new lightweight 57 mm cannon was an absolute success as "pocket artillery" for the soldiers of U.S. Army infantry units that were issued the M18. It was first used in the Pacific Theater during the Battle of Okinawa on June 9, 1945, and proved with its HE and white phosphorus rounds it was the perfect weapon for the hard fighting that took place against the dug-in Japanese in the hills of that island. The only complaint the U.S. Army had was the lack of sufficient 57 mm ammunition for the M18. [14]
Each U.S. Army rifle company in the Korean War was authorized three M18 recoilless rifles. [15] The Marine Corps did not use the 57mm. Veterans of the Korean War have mentioned the use of the M18 against enemy machine gun nests. [16] For anti-tank tasks, however, the M18 was too weak; the Soviet-built T-34 tank was extremely hard to penetrate even for the 2.36-inch (60 mm) Bazooka of World War II. The only way would have been flank or rear shots. U.S. infantry, initially with very few capabilities against these targets, solved the problem with new weapons like the 3.5-inch (89 mm) M20 Super Bazooka, which was powerful enough to destroy T-34s. [17]
Although obsolete as an anti-tank weapon, the M18 was still used by the Army of the Republic of Vietnam [18] and its allied forces in an anti-personnel role. It was able to use the NATO-standard M74 tripod, and proved with its HE and white phosphorus rounds it was the perfect weapon for the hard fighting that took place against dug-in People's Army of Vietnam forces.
Ammunition for the 57 mm M18 consisted of fixed rounds; that is to say, the propelling charge is not adjustable and an integral part of the ammunition. It is easily identified by a pre-engraved rotating band, a perforated cartridge case, and a positioning band.
In 1948, four types of round were available for the 57 mm M18, with a canister round [19] (with a range of 160 meters) being added later:
Type of round | Weight of round | Length of round | Weight of projectile as fired | Type of filler | Weight of filler | Weight of propellant | Type of fuze | Action of fuze | Weight of 4 rounds in a box | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
lb | kg | inch | mm | lb | kg | lb | g | lb | g | lb | kg | ||||
HE (M306) | 5.3 | 2.4 | 17.54 | 446 | 2.75 | 1.25 | TNT | .6 | 270 | .93 | 420 | M89 | PD, SQ | 44 | 20 |
HEAT (M307) | 5.3 | 2.4 | 18.78 | 477 | 2.75 | 1.25 | 50/50 Pentolite | .39 | 180 | .93 | 420 | M90 | PI, BD non-delay | 45 | 20 |
Smoke WP (M308) | 5.3 | 2.4 | 16.83 | 427 | 2.75 | 1.25 | WP | .27 | 120 | .93 | 420 | M89 | PD, SQ | 43 | 20 |
TP (M306) | 5.3 | 2.4 | 17.54 | 446 | 2.75 | 1.25 | Inert and black powder | .45 and .07 | 204 and 32 | .93 | 420 | M89 | PD, SQ | 42 | 19 |
Canister (T25E5) | 5.43 | 2.46 | 15.48 | 393 | - | - | 154 or 176 steel slugs | 1.8 | 820 | .93 | 420 | N/A | N/A |
The M18 was copied by the People's Republic of China as the Type 36. The U.S. had provided Nationalist China the blueprints for the weapon. When the communist Chinese seized the factory, they took advantage of the facilities and blueprints to make their own copy of the weapon. [20] China provided the communist Vietnamese the Type 36 in 1963 for use in the Vietnam War. [21] Tanzania was also a user of the Type 36. In a strange twist, the Chinese version of the M18 can fire both U.S. and Chinese manufactured ammunition, but the U.S. made M18s cannot fire Chinese ammunition. [5] This was done deliberately by increasing the bore of their weapons and ammunition by 1 mm, making their munitions too large for use by NATO weapons in the event of capture, but not vice versa. The French army also used M18 guns during the First Indochina War, [22] Algerian War [23] [24] and French intervention in Сhad in 1970. [25]
As late as 1984, the M18 57 mm recoilless rifle was still being produced under license in Brazil by Hydroar in São Paulo. [20]
A rocket-propelled grenade (RPG) is a shoulder-fired rocket weapon that launches rockets equipped with an explosive warhead. Most RPGs can be carried by an individual soldier, and are frequently used as anti-tank weapons. These warheads are affixed to a rocket motor which propels the RPG towards the target and they are stabilized in flight with fins. Some types of RPG are reloadable with new rocket-propelled grenades, while others are single-use. RPGs are generally loaded from the front.
A recoilless rifle (rifled), recoilless launcher (smoothbore), or simply recoilless gun, sometimes abbreviated to "RR" or "RCL" is a type of lightweight artillery system or man-portable launcher that is designed to eject some form of countermass such as propellant gas from the rear of the weapon at the moment of firing, creating forward thrust that counteracts most of the weapon's recoil. This allows for the elimination of much of the heavy and bulky recoil-counteracting equipment of a conventional cannon as well as a thinner-walled barrel, and thus the launch of a relatively large projectile from a platform that would not be capable of handling the weight or recoil of a conventional gun of the same size. Technically, only devices that use spin-stabilized projectiles fired from a rifled barrel are recoilless rifles, while smoothbore variants are recoilless guns. This distinction is often lost, and both are often called recoilless rifles.
A bazooka is a man-portable recoilless anti-tank rocket launcher weapon, widely deployed by the United States Army, especially during World War II. Also referred to as the "stovepipe", the innovative bazooka was among the first generation of rocket-propelled anti-tank weapons used in infantry combat. Featuring a solid-propellant rocket for propulsion, it allowed for high-explosive anti-tank (HEAT) shaped charge warheads to be delivered against armored vehicles, machine gun nests, and fortified bunkers at ranges beyond that of a standard thrown grenade or mine. The universally applied nickname arose from the M1 variant's vague resemblance to the musical instrument called a bazooka invented and popularized by 1930s American comedian Bob Burns.
High-explosive anti-tank (HEAT) is the effect of a shaped charge explosive that uses the Munroe effect to penetrate heavy armor. The warhead functions by having an explosive charge collapse a metal liner inside the warhead into a high-velocity shaped charge jet; this is capable of penetrating armor steel to a depth of seven or more times the diameter of the charge. The shaped charge jet armor penetration effect is purely kinetic in nature; the round has no explosive or incendiary effect on the armor.
Anti-tank warfare originated during World War I from the desire to develop technology and tactics to destroy tanks. After the Allies deployed the first tanks in 1916, the German Empire introduced the first anti-tank weapons. The first developed anti-tank weapon was a scaled-up bolt-action rifle, the Mauser 1918 T-Gewehr, that fired a 13.2 mm cartridge with a solid bullet that could penetrate the thin armor used by tanks at that time and destroy the engine or ricochet inside, killing occupants. Because tanks represent an enemy's strong force projection on land, military strategists have incorporated anti-tank warfare into the doctrine of nearly every combat service since. The most predominant anti-tank weapons at the start of World War II in 1939 included the tank-mounted gun, anti-tank guns and anti-tank grenades used by the infantry, and ground-attack aircraft.
Ontos, officially the Rifle, Multiple 106 mm, Self-propelled, M50, was an American light armored tracked anti-tank vehicle developed in the 1950s.
Shoulder-fired missile, shoulder-launched missile or man-portable missile, among other variants, are common slang-terms to describe high-caliber shoulder-mounted weapons systems – that is: weapons firing large heavy projectiles ("missiles"), typically using the backblast principle, which are small enough to be carried by a single person and fired while held on one's shoulder. The word "missile" in this context is used in its original broad sense of a heavy projectile, and encompasses all shells and rockets, guided or unguided. A more formal variant is simply shoulder-fired weapons system and the like.
An anti-tank rifle is an anti-materiel rifle designed to penetrate the armor of armored fighting vehicles, most commonly tanks, armored personnel carriers, and infantry fighting vehicles. The term is usually used for weapons that can be carried and used by one person, but is sometimes used for larger weapons. The usefulness of rifles for this purpose ran from the introduction of tanks in World War I until the Korean War. While medium and heavy tank armor became too thick to be penetrated by rigid projectiles from rifles that could be carried by a single soldier, anti-tank rifles continued to be used against other "soft" targets, though recoilless rifles and rocket-propelled grenades such as the bazooka were also introduced for infantry close-layer defense against tanks.
The Carl Gustaf 8.4 cm recoilless rifle is a Swedish-developed 84 mm (3.3 in) caliber shoulder-fired recoilless rifle, initially developed by the Royal Swedish Army Materiel Administration during the second half of the 1940s as a crew-served man-portable infantry support gun for close-range multi-role anti-armour, anti-personnel, battlefield illumination, smoke screening and marking fire, which has seen great export success around the globe and continues to be a popular multi-purpose support weapon in use by many nations. The Carl Gustaf 84 mm recoilless rifle is a lightweight, low-cost weapon that uses a wide range of ammunition, which makes it extremely flexible and suitable for a wide variety of roles.
The Vietnam War involved the People's Army of Vietnam (PAVN) or North Vietnamese Army (NVA), National Liberation Front for South Vietnam (NLF) or Viet Cong (VC), and the armed forces of the People's Liberation Army (PLA), Army of the Republic of Vietnam (ARVN), United States Armed Forces, Republic of Korea Armed Forces, Armed Forces of the Philippines, Royal Thai Armed Forces, Australian Defence Force, and New Zealand Defence Force, with a variety of irregular troops.
An anti-tank gun is a form of artillery designed to destroy tanks and other armoured fighting vehicles, normally from a static defensive position. The development of specialized anti-tank munitions and anti-tank guns was prompted by the appearance of tanks during World War I. To destroy hostile tanks, artillerymen often used field guns depressed to fire directly at their targets, but this practice expended too much valuable ammunition and was of increasingly limited effectiveness as tank armor became thicker. The first dedicated anti-tank artillery began appearing in the 1920s, and by World War II was a common appearance in many European armies. To penetrate armor, they fired specialized ammunition from longer barrels to achieve a higher muzzle velocity than field guns. Most anti-tank guns were developed in the 1930s as improvements in tanks were noted, and nearly every major arms manufacturer produced one type or another.
The M67 recoilless rifle is a 90 mm anti-tank recoilless rifle made in the United States and later in South Korea. It could also be employed in an anti-personnel role with the use of the M590 antipersonnel round. It was designed to be fired primarily from the ground using the bipod and monopod, but could also be fired from the shoulder using the folded bipod as a shoulder rest and the monopod as a front grip. The weapon was air-cooled and breech-loaded, and fired fixed ammunition. It is a direct fire weapon employing stadia lines to allow simple range finding, based on a typical tank target bridging the lines once in range.
The Ordnance Quick-Firing 6-pounder 7 cwt, or just 6-pounder, was a British 57 mm gun, serving during the Second World War as a primary anti-tank gun of both the British and United States Army. It was also used as the main armament for a number of armoured fighting vehicles.
The M40 recoilless rifle is a portable, crew-served 105 mm recoilless rifle made in the United States. Intended primarily as an anti-tank weapon, it could also be employed in an antipersonnel role with the use of an antipersonnel-tracer flechette round. The bore was commonly described as being 106 mm caliber but is in fact 105 mm; the 106 mm designation was intended to prevent confusion with incompatible 105 mm ammunition from the failed M27. The air-cooled, breech-loaded, single-shot rifle fired fixed ammunition and was used primarily from a wheeled ground mount. It was designed for direct firing only, and sighting equipment for this purpose was furnished with each weapon, including an affixed spotting rifle.
The M20 recoilless rifle is a U.S. 75 mm caliber recoilless rifle T21E12 that was used during the last months of the Second World War and extensively during the Korean War. It could be fired from an M1917A1 .30 caliber machine gun tripod, or from a vehicle mount, typically a Jeep. Its shaped charge warhead, also known as HEAT, was capable of penetrating 100 mm of armor. Although the weapon proved ineffective against the T-34 tank and most other tanks during the Korean War, it was used primarily as a close infantry support weapon to engage all types of targets including infantry and lightly armored vehicles. The M20 proved useful against pillboxes and other types of field fortifications.
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