The M18 recoilless rifle was a shoulder fired anti-tank weapon that was used by the United States military during World War II, the Chinese Civil War, the Korean War, and, to a lesser extent, the Vietnam War.


The M18 required a two-man crew to fire its 57 mm rounds. The weapon was breech-loaded and only capable of firing a single shot before reloading. For proper firing, the M18 was traditionally fired from a bipod, with one conveniently provided by opening up the weapon's shoulder mount[1], but could just as well make due with a standard American machine gun tripod mount or simply from the operator's shoulder. The M18 was provided with three choices for ammunition, HE (High Explosive), WP (White Phosphorous), or HEAT (High Explosive Anti-Tank)[2] with the last being capable of penetrating roughly 75 mm of armor plate angled at 90˚ when firing within the effective range of 400 meters.[3] The fuse of the HE round was reported to be sensitive enough to detonate upon hitting foliage, ideal for the elimination of hidden snipers.[4] Compared to the contemporary M1 Bazooka, the M18 was noted for its significantly better accuracy and greater maximum range of over 4,000 meters.[3]

However, the M18 did have its fair share of flaws, including a particularly big backblast and use of propellant charge, creating an obvious signal as to the firing location. Furthermore, the ammunition for the weapon was considerably more expensive and heavy as was the actual weapon itself which weighed about 19 kilograms and measured 1.1 meters.


The M18 was developed under the name T15 from 1943 to 1944 by the Small Arms Development Division of the Army Ordnance's Research and Development service[1] before finally being issued to American troops as a mobile infantry anti-tank weapon in early 1945. The weapon was also put into combat alongside the larger 75 mm M20 Recoilless Rifle. In Europe, the M18 first saw combat with the 17th Airborne Division, while in the Pacific, the M18 was used alongside the M20 to attack Japanese defensive positions during the Battle of Okinawa.[1] While mostly innefective in the European Theatre[Note 1] , on Okinawa, the M18 proved exceptionally useful in the role of highly mobile, infantry artillery, capable of relocating and reacting to the combat situation as it progressed.

Following the war, the M18 continued to have its uses in the arsenal of the United States Army, being used up until the Vietnam War, still in the role discovered for it during the fighting on Okinawa.


  1. The standard M1 Bazooka had much greater penetration ability than the M18, and was still struggling against German tanks


  1. 1.0 1.1 1.2 Popular Science (June 1945), Page 86 Article Link
  3. 3.0 3.1
  4. Popular Science. (June 1945), Page 238 Article Link

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