ABOUT WEAPON
The M18 recoilless rifle was a shoulder fired antitank weapon 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 cannons, but with greater accuracy than antitank 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 antitank and antipersonnel roles. It was fired using a monopod or from the shoulder. The most stable firing position was from the tripod developed for the water cooled Browning M1917 machine gun.
During World War Two, the U.S. Army's Artillery Section was working on a 105-mm recoilless cannon, based on captured German models 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 blow out plug, the Infantry Section's recoilless cannon used a British development 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. 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 cannons had at that time period achieved.
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. 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: an antitank HEAT round, an HE round, a smoke shell using white phosphorus, and a training round. By early 1945, over 2,000 M18 recoilless rifles and 800,000 rounds of ammunition were on order.
The first production M18 57-mm cannons and ammunition were rushed from the factories to the European and Pacific war theaters. The first combat the new cannon saw was with the U.S. Army's17th Airborne Division near Essen, Germany. While impressed with the fire power available in a lightweight weapon with the HE round, the M18's 57mm HEAT round was a disappointment with only 63.5mm of penetration, compared with the older M1A1 Bazooka which had a penetration of nearly 120mm. The reason for the disappointing penetration by the M18's 57-mm HEAT round was the problem any HEAT round will have if it is fired from a cannon that uses rifling to stabilize the projectile after it leaves the muzzle. Spinning degrades the penetration of HEAT rounds.
In the Pacific Theater, the new lightweight 57mm 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 WP 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.
Veterans of the Korean War have mentioned the use of the M18 against enemy machine gun nests. As for anti-tank tasks, however, the M18 was too weak; the T-34 tank was extremely hard to penetrate even for the 2.36 inch (60mm) Bazooka of WW2 had almost no chance to kill it; the only way could had been flank or rear shots; US Infantry, initially with very few capabilities against these target, solved the problem with new weapons, like the 3.5 inch (89mm) M20 Super Bazooka was powerful enough to kill T-34s.
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 communists seized the factory, they took advantage of the facilities and blueprints to make their own copy of the weapon. China provided the Vietnamese communists the Type 36 in 1963 for use in the Vietnam War.Tanzania was also a user of the Type 36. In a strange twist, the Chinese version of the M18 can fire both US and Chinese manufactured ammunition, but US made M18s can not fire Chinese ammunition. As late as 1984, the M18 57-mm recoilless rifle was still being produced under license in Brazil by Hydroar in Sao Paulo.
Service history |
Wars |
World War II
Korean War |
Production history |
Designed |
1943 |
Specifications |
Weight |
22.04 kg (48.6 lb) |
Length |
1.56 m (5.1 ft) |
Crew |
2 |
|
Shell |
57303 mm. R (HEAT, HE, WP) |
Caliber |
57 mm. (2.26 inches) |
Muzzle velocity |
365 m/s |
Effective range |
450 m (0.28 mi) |
Maximum range |
3,976 m (2.471 mi) |
Sights |
M26 Scope |
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