Design and development The development of the bazooka involved the development of two specific lines of technology: the rocket-powered weapon and the
shaped charge warhead. It was also designed for easy maneuverability and access.
World War I This rocket-powered weapon was the brainchild of
Robert H. Goddard as a side project (under U.S. Army contract during World War I) of his work on rocket propulsion. Goddard, during his tenure at
Clark University, and while working at
Worcester Polytechnic Institute's magnetic lab and
Mount Wilson Observatory (for security reasons), designed a tube-fired rocket for military use. He and his co-worker
Clarence N. Hickman successfully demonstrated his rocket to the
U.S. Army Signal Corps at
Aberdeen Proving Ground, Maryland, on November 6, 1918, but as the
Compiègne Armistice was signed only five days later, development was discontinued. The project was also interrupted by Goddard's serious bout with
tuberculosis. He continued to be a part-time consultant to the U.S. government at
Indian Head, Maryland, until 1923, but turned his focus to other projects involving rocket propulsion. Hickman completed the development of the bazooka after becoming head of the
National Defense Research Committee in the 1940s, where he guided rocket development for the war effort.
Shaped charge development Shaped charge technology was developed in the U.S. into a shaped charge
anti-tank grenade for use by infantry, effective at defeating up to 60 mm (2.4 in) of
vehicle armor. The grenade was standardized as the M10. However, the M10 grenade weighed 3.5 lb (1.6 kg), proving difficult to throw by hand and too heavy to be launched as a
rifle grenade. The only practical way to use the weapon was for an infantryman to place it directly on the tank, a dangerous and unlikely means of delivery in most combat situations. A smaller, less powerful, version of the M10, the
M9, was then developed, which could be fired from a rifle. This resulted in the creation of a series of rifle grenade launchers, the M1 (
Springfield M1903), the M2 (
Enfield M1917), the
M7 (
M1 Garand), and the M8 (
M1 carbine). However, a truly capable anti-tank weapon had yet to be found, and following the lead of other countries at the time, the U.S. Army prepared to evaluate competing designs for a more effective man-portable anti-tank weapon. The combination of rocket motor and shaped charge warhead led to the Army's development of light antitank weapons.
Rocket-borne shaped charge weapons development In 1942, U.S. Army Colonel
Leslie Skinner received the M10 shaped-charge grenade which was capable of stopping German tanks. He gave Lieutenant
Edward Uhl the task of creating a delivery system for the grenade. Uhl created a small rocket, but needed to protect the operator from the rocket motor's exhaust. According to Uhl: At the launcher's first firing test, Uhl wore a
welding helmet, but discovered that there was not enough exhaust from the rocket to require protective equipment. The prototype launcher was demonstrated in May 1942 at a competitive trial of various types of
spigot mortars at Aberdeen Proving Ground. On the morning of the trial Skinner and Uhl realised that the launcher had no sights, so they improvised some from a wire coathanger; despite this, it was the only weapon in the trial to be able to hit a moving tank. This led to the launcher being demonstrated to General
George C. Marshall, the
Chief of Staff of the United States Army, who ordered 5,000 units on the spot. By late 1942, the improved
Rocket launcher, M1A1 was introduced. The forward hand grip was deleted, and the design simplified. The production M1A1 was 55 inches (1.37 m) long and weighed 12.75 pounds (5.8 kg). The ammunition for the original M1 launcher was the M6 ("trials" code: T1), which was notoriously unreliable. The M6 was improved and designated
M6A1, and the new ammunition was issued with the improved M1A1 launcher. After the M6, several alternative warheads were introduced. Many older M1 launchers were modified to M1A1 standards in July and August 1943. Batches of M6 rockets designated
M6A2 were overhauled with the latest ignition systems and had been modified to be able to be fired from the upgraded M1 launchers. The M6A3 rocket featured a blunt, rounded nose to lessen the chances of it ricocheting off angled armor. The M6A3 was meant to be fired from the M9, and later M9A1, launchers. Late in World War II, the M6A4 and M6A5 rockets with improved fuses were developed. These rockets arrived too late to see service during the war, but were used post-war. The 2.36 inch (60 mm) smoke rocket M10 and its improved subvariants (M10A1, M10A2, M10A4) used the rocket motor and fin assembly of the M6A1, but replaced the anti-tank warhead with a
white phosphorus (WP) smoke head. WP smoke not only acts as a visibility screen, but its burning particles can cause severe injuries to skin. The M10 was therefore used to mark targets, to blind enemy gunners or vehicle drivers, or to drive troops out of bunkers and dugouts. The 2.36-inch incendiary rocket T31 was an M10 variant with an incendiary warhead designed to ignite fires in enemy-held structures and unarmored vehicles, or to destroy combustible supplies, ammunition, and
materiel; it was not often utilized. The original M1 and M1A1 rocket launchers were equipped with simple fixed sights and used launch tubes without reinforcements. During the war, the M1A1 received a number of running modifications. The battery specification was changed to a larger, standard battery cell size, resulting in complaints of batteries getting stuck in the wood shoulder rest (the compartment was later reamed out to accommodate the larger cells). The M1 and M1A1 used rear iron sights and front rectangular "ladder" sights positioned at the muzzles. The vertical sides of the ladder sight were inscribed with graduations of 100, 200, 300, and 400 yards, with the user elevating the bazooka so the rear sight lined up with the selected "rung" on the front sight. On the M9, the ladder sight was replaced by the General Electric T43 aperture sight. Ranging was accomplished by looking through the rear sight's peep hole while rotating the assembly (which had graduations of 100, 200, and 300 yards) so it lined up with the blade positioned at the muzzle. In September 1944, during the production of the M9A1, the T43 sight was replaced by the Polaroid T90 optical reflector sight, which used an etched
reticle for aiming. The T43 and T90 sights were interchangeable. Various types of blast deflectors were tried, and an additional strap iron shoulder brace was fitted to the M9 launcher. The bazooka required special care when used in tropical or arctic climates or in severe dust or sand conditions. Rockets were not to be fired at temperatures below 0 °F or above 120 °F (−18 °C to +49 °C).
Field experience-induced changes In 1943, field reports of rockets sticking and prematurely detonating in M1A1 launch tubes were received by Army Ordnance at Ogden Arsenal and other production facilities. At the U.S. Army's Aberdeen Proving Grounds, various metal collars and wire wrapping were used on the sheet metal launch tube in an effort to reinforce it. However, reports of premature detonation continued until the development of bore slug
test gauges to ensure that the rocket did not catch inside the launch tube. The original M6 and M6A1 rockets used in the M1 and M1A1 launchers had pointed noses, which were found to cause
deflection from the target at low impact angles. In late 1943, another 2.36-in rocket type was adopted, the M6A3, for use with the newly standardized M9 rocket launcher. CK, a deadly blood agent, was capable of penetrating the protective filter barriers in some gas masks, and was seen as an effective agent against Japanese forces (particularly those hiding in caves or bunkers), whose gas masks lacked the impregnants that would provide protection against the chemical reaction of CK. While stockpiled in US inventory, the CK rocket was never deployed or issued to combat personnel. This margin allowed him to eventually mount a total of six Bazookas, three per side on the lift struts as other L-4s had done. Within a few weeks, Carpenter was credited with knocking out a German armored car and four tanks. Carpenter's plane was known as "Rosie the Rocketer," and his exploits were soon featured in press accounts. During the critical late-September
Battle of Arracourt, Carpenter managed to disable several German armored cars and two
Panther tanks, along with killing or wounding a dozen or more enemy soldiers. In the opening months of the
Korean War, in August 1950, a joint U.S. Navy and Marine Corps test used a newly acquired
Bell HTL-4 helicopter to test if a bazooka could be fired from a helicopter in flight. One of the larger, 3.5 inch, models of the bazooka was chosen, and was mounted ahead and to the right of the helicopter to allow the door to remain clear. The bazooka was successfully tested, although it was discovered that it would require shielding for the engine compartment, which was exposed in the model 47 and other early helicopters. The helicopter itself belonged to HMX-1, a marine experimental helicopter squadron.
Operational use World War II In September 1942, a consignment of 600 M1 Bazookas was shipped to Egypt for use by the British Army in the
Western Desert campaign. In a demonstration to British commanders, a bazooka penetrated the frontal armor of a captured
Panzer III; however it was decided that the desert terrain lacked the concealment required for such a short range weapon and it was not deployed in that theater. In November 1942 during
Operation Torch, early production versions of the M1 launcher and M6 rocket were hastily supplied to some of the U.S. invasion forces during the landings in
North Africa. On the night before the landings, General
Dwight D. Eisenhower was shocked to learn from a subordinate that none of his troops had received any instruction in the use of the bazooka. Initially supplied with the highly unreliable M6 rocket and without training for its operators, the M1 did not play a significant armed role in combat in the North African fighting, but did provide a German intelligence coup In late 1942, numbers of early-production American M1 Bazookas were captured by German troops from Red Army forces who had been given quantities under
Lend-Lease. There were also examples captured during the Operation Torch invasions in the North African Campaign. In the hands of American infantry the bazooka still enjoyed rare successes against heavy Nazi armored fighting vehicles. In 1945, during the failed German
Operation Nordwind offensive, a bazooka team managed the unlikely achievement of destroying a
Jagdtiger heavy tank destroyer, the most heavily armored fighting vehicle of World War II. The team managed to do this by positioning themselves to get a shot at the massive vehicle's thinner side armor, scoring a direct hit on the ammunition bustle and causing a
catastrophic kill. This incident shows that when correctly aimed at vulnerable points on vehicles the bazooka could still be effective against even the best-protected of armored vehicles, though it required significant skill to accomplish. with
Schürzen armor skirts In a letter dated May 20, 1944, General
George S. Patton stated to a colleague that "the purpose of the Bazooka is not to hunt tanks offensively, but to be used as a last resort in keeping tanks from overrunning infantry. To insure this, the range should be held to around 30 yards." In the Pacific campaign, as in North Africa, the original bazookas sent to combat often had reliability issues. The battery-operated firing circuit was easily damaged during rough handling, and the rocket motors often failed because of high temperatures and exposure to moisture, salt air, or humidity. With the introduction of the M1A1 and its more reliable rocket ammunition, the bazooka was effective against some fixed Japanese infantry emplacements such as small concrete bunkers and
pillboxes. Against coconut and sand emplacements, the weapon was not always effective, as these softer structures often reduced the force of the warhead's impact enough to prevent detonation of the explosive charge. Later in the Pacific war, Army and Marine units often used the
M2 flamethrower to attack such emplacements. In the few instances in the Pacific where the bazooka was used against tanks and armored vehicles, the rocket's warhead easily penetrated the thin armor used by the Japanese and destroyed the vehicle. Overall, the M1A1, M9, and M9A1 rocket launchers were viewed as useful and effective weapons during World War II, though they had been primarily employed against enemy emplacements and fixed fortifications, not as anti-tank weapons. General Dwight Eisenhower later described it as one of the four "tools of victory" which won World War II for the Allies (together with the
atom bomb,
Jeep and the
C-47 Skytrain transport aircraft). During the war, bazookas were provided by Lend-Lease to the United Kingdom, Brazil, Canada, China, and
Free French forces as well as the
Soviet Union. Some were supplied to French
maquis and
Yugoslav partisans.
Korean War The success of the more powerful German
Panzerschreck caused the bazooka to be completely redesigned at the close of World War II. A larger, 3.5 in (89 mm) model was adopted, the M20 "Super Bazooka". Though bearing a superficial resemblance to the
Panzerschreck, the M20 had greater effective range and penetrating capability and was nearly 20% lighter than its German counterpart. The M20 weighed 14.3 pounds (6.5 kg) and fired a hollow shaped-charge 9 lb (4 kg) M28A2 HEAT rocket when used in an anti-tank role. It was also operated by a two-man team and had a rate of fire of six shots per minute. As with its predecessor, the M20 could also fire rockets with either practice (M29A2) or WP smoke (T127E3/M30) warheads. Having learned from experience of the sensitivity of the bazooka and its ammunition to moisture and harsh environments, the ammunition for the new weapon was packaged in moisture-resistant packaging, and the M20's field manual contained extensive instructions on launcher lubrication and maintenance, as well as storage of rocket ammunition. When prepared for shipment from the arsenal, the weapon was protected by antifungal coatings over all electrical contacts, in addition to a
cosmoline coating in the hand-operated magneto that ignited the rocket. Upon issue, these coatings were removed with solvent to ready the M20 for actual firing. However, budget cutbacks initiated by Secretary of Defense
Louis A. Johnson in the years following World War II effectively canceled the intended widespread issue of the M20, and initial U.S. forces deploying to Korea were armed solely with the M9/M9A1 2.36-in. launcher and old stockpiled World War II inventories of M6A3 rocket ammunition. At the outbreak of the
Korean War, the South Korean military had 1,958 M9A1 rocket launchers that were given by the U.S. Forces Korea during the withdrawal in 1948 to 1949, the only anti-tank firearms that the South Koreans had secured in sufficient quantities. However, the 2.36-inch rocket launcher could not penetrate the front armor of
T-34-85s, which were the biggest threat. The South Koreans responded by firing rockets into the side, rear, or tracks through ambushes, but they did not have much effect. At the same time, the U.S. military dispatched its first troops to the Korean Peninsula without trusting reports that a 2.36-inch rocket could not destroy North Korean tanks. On July 5, 1950, during the
Battle of Osan,
Task Force Smith tried to stop North Korean tanks with 2.36-inch rocket launchers and 75 mm recoilless rifles but was overrun by 33 T-34-85s. One of the North Korean T-34s received a total of 22 shots on the side and rear at about 10 meters in distance, but survived. and the Chinese later reverse engineered and produced a copy of the M20 designated the
Type 51. It is considered that the Communist-used bazookas destroyed more tanks than the UN bazookas did.
Vietnam War The M20 was used in the early stages of the war in Vietnam by the U.S. Marines before gradually being phased out by the mid-1960s in favor of the
M67 recoilless rifle and later, the
M72 LAW rocket. The U.S. Army also used it in lesser quantity. While occasions to destroy enemy armored vehicles proved exceedingly rare, it was employed against enemy fortifications and emplacements with success. The M20 remained in service with South Vietnamese and indigenous forces until the late 1960s. The Vietnam People's Army also developed their own bazooka under the management of
Tran Dai Nghia. It was successfully test-fired in 1947. The anti-French
Viet Minh received Chinese Type 51 bazookas. They were used by the
Viet Cong as late as 1964. and
Algeria. The M20A1 was replaced in the 1970s by the
LRAC F1.
Commonwealth armies also used the M20 and M20A1 under the name
M20 Mk I and
M20 Mk II. They were used until their replacement by the
Carl Gustav L14A1. For instance, British Army used Super Bazookas during the
Operation Vantage. The
Argentine Army fielded M20s during the
Falklands War. ==Variants==