Bazooka

Bazooka is the common name for a man-portable recoilless antitank rocket launcher weapon, widely fielded by the United States Army. Also referred to as the "Stovepipe", the innovative bazooka was amongst the first-generation of rocket propelled anti-tank weapons used in infantry combat. Featuring a solid rocket motor for propulsion, it allowed for high-explosive anti-tank (HEAT) 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 Bazooka also fired a HESH round, effective against buildings and tank armour. The universally-applied nickname arose from the M1 variant's vague resemblance to the musical instrument called a "bazooka" invented and popularized by 1930s U.S. comedian Bob Burns.

During World War II, German armed forces captured several bazookas in early North African and Eastern Front encounters and soon reverse engineered their own version, increasing the warhead diameter to 8.8 cm (amongst other minor changes) and widely issuing it as the Raketenpanzerbüchse "Panzerschreck" ("Tank terror").

The term "bazooka" continues to be used informally as a genericized term to refer to any shoulder-fired missile weapon (mainly rocket propelled grenades).

Design and development
The development of the bazooka involved the development of two specific lines of technology: the rocket-powered (recoilless) weapon, and the shaped-charge warhead. It was also designed for easy maneuverability and access.

World War I
The Rocket-Powered Recoilless Weapon was the brainchild of Dr. Robert H. Goddard as a side project (under Army contract) of his work on rocket propulsion. Goddard, during his tenure at Clark University, and while working at Worcester Polytechnic Institute's magnetics lab and Mount Wilson Observatory (for security reasons), designed a tube-fired rocket for military use during World War I. He and his co-worker, Dr. Clarence Hickman, successfully demonstrated his rocket to the US Army Signal Corps at Aberdeen Proving Ground, Maryland, on November 6, 1918, but as the Compiègne Armistice was signed only five days later, further development was discontinued. The delay in the development of the bazooka was as a result of Goddard's serious bout with tuberculosis. Goddard continued to be a part-time consultant to the US government at Indian Head, Maryland, until 1923, but soon turned his focus to other projects involving rocket propulsion.

The shaped charge
Development of the explosive shaped charge dates back to the work of American physicist Charles Edward Munroe, who carried out explosive shock focusing experiments in 1880. For over 50 years the phenomenon remained a curiosity. Around or during 1937 however, two apparently (but potentially not) independent groups of German and Swiss inventors began promoting shaped-charge devices for application as anti-armor weapons. The picture is clouded by secrecy in the buildup to World War II; the German group of Cranz, Schardin, and Thomanek went on to develop weapons for the German war effort, while the group led by the Swiss inventor Henry Mohaupt licensed their designs internationally.

Mohaupt's technology was developed in the US into a shaped charge hand grenade for use in highly fluid situations, 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), was 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, an 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), M2 (Enfield M1917), and the M7 (M1 Garand) and 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 large and powerful anti-tank rifle.

The combination of rocket motor and shaped charge warhead would put paid to Army development of light antitank guns.

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 tasked Lieutenant Edward Uhl with creating a delivery system for the grenade. Uhl created a small rocket, but needed to protect the firer from the rocket exhaust and aim the weapon. According to Uhl,

"I was walking by this scrap pile, and there was a tube that... happened to be the same size as the grenade that we were turning into a rocket. I said, That's the answer! Put the tube on a soldier's shoulder with the rocket inside, and away it goes.""

By late 1942, the improved Rocket Launcher, M1A1 was introduced. The forward hand grip was deleted, and the design simplified. The production M1A1 was 54 inches (1.37 m) long and weighed only 12.75 pounds (5.8 kg).

The ammunition for the original M1 launcher was the M6, 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. The 2.36-inch 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 visible screen, but its burning particles can cause burns on human 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 a simple rear sight and fixed front sight, and used a launch tube 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). This was followed by a new aperture rear sight and a front rectangular "frame" sight positioned at the muzzle. The vertical sides of the frame sight were inscribed with graduations of 100, 200, and 300 yards. On the M9, the iron sights were at first replaced by a plastic optical ring sight, which proved unsatisfactory in service, frequently turning opaque after a few days' exposure to sunlight. Later iron sights were hinged to fold against the tube when not in use, and were protected by a cover. The launcher also had an adjustable range scale that provided graduations from 50 to 700 yards (46 to 640 meters) in 50-yard (46 m) increments. An additional strap iron shoulder brace was fitted to the launcher, along with various types of blast deflectors.

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 zero 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 US Army's Aberdeen Testing 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 a pointed nose, which was 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. The M6A3 was 19.4 inches (493 mm) long, and weighed 3.38 lb (1.53 kg). It had a blunted, more round nose to improve target effect at low angles, and a new circular fin assembly to improve flight stability. The M6A3 was capable of penetrating 3.5 to 4 inches (89 to 102mm) of armor plate.

Battery problems in the early bazookas eventually resulted in replacement of the battery-powered ignition system with a magneto sparker system operated through the trigger. A trigger safety was incorporated into the design that isolated the magneto, preventing misfires that could occur when the trigger was released and the stored charge prematurely fired the rocket. The final major change was the division of the launch tube into two discrete sections, with bayonet-joint attachments. This was done to make the weapon more convenient to carry, particularly for use by airborne forces. The final two-piece launcher was standardized as the M9A1. However, the long list of incorporated modifications increased the launcher's tube length to 61 inches (1.55 m), with an overall empty weight of 14.3 lb (6.5 kg). From its original conception as a relatively light, handy, and disposable weapon, the final M9A1 launcher had become a heavy, clumsy, and relatively complex piece of equipment.

In October 1944, after receiving reports of inadequate combat effect of the M1A1 and M9 launchers and their M6A1 rockets, and after examining captured examples of the German 8.8 cm RPzB 43 and RPzB 54 Panzerschreck, the US Ordnance Corps began development on a new, more powerful anti-tank rocket launcher, the 3.5-inch M20. However, the weapon's design was not completed until after the war and saw no action against an enemy until Korea.

In 1945, the U.S. Army's Chemical Warfare Service standardized improved chemical warfare rockets intended for the new M9 and M9A1 launchers, adopting the M26 Gas Rocket, a cyanogen chloride (CK)-filled warhead for the 2.36-in 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.

World War II
Secretly introduced via the Russian front and 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, Gen. Dwight D. Eisenhower was shocked to discover 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, the M1 did not play a significant armed role in combat in the North African fighting, but did provide a German intelligence coup when some were captured by the Germans in early encounters with inexperienced US troops. A US general visiting the Tunisian front in 1943 after the close of combat operations could not find any soldiers who could report that the weapon had actually stopped an enemy tank. Further issue of the bazooka was suspended in May 1943.

During the Allied invasion of Sicily, small numbers of the M1A1 bazooka (using an improved rocket, the M6A1) were used in combat by US forces. The M1A1 accounted for four medium German tanks and a heavy Tiger I, with the latter being knocked out by a lucky hit through the driver's vision slot. A major disadvantage to the bazooka was the large backblast and smoke trail (in colder weather), which gave away the position of the shooter, mandating quick relocation of the squad. Moreover, the bazooka fire team often had to expose their bodies in order to obtain a clear field of fire against an armored target. Casualties among bazooka team members were extremely high during the war, and assignment to such duty, widely known as Medal of Honor work, in the face of German counterfire was typically regarded by other platoon members as not only highly dangerous, but nearly suicidal.

When the existence of the bazooka was revealed to the American public official press releases for the first two years stated that it "packed the wallop of a 155mm cannon"—a great exaggeration, but widely accepted by the American public at the time.

In late 1942, numbers of early-production American M1 bazookas were captured by German troops from Russian forces who had been given quantities of the bazooka under Lend-Lease as well as during the Operation Torch invasions in the North African Campaign. The Germans promptly developed their own version of the weapon, increasing the diameter of the warhead from 60 mm to 88 mm (2.4 to 3.5 in). In German service, the bazooka was popularly known as the Panzerschreck. The German weapon, with its larger, more powerful warhead, had significantly greater armor penetration; ironically, calls for a larger-diameter warhead had also been raised by some ordnance officers during U.S. trials of the M1, but were rejected. After participating in an armor penetration test involving a German Panther tank using both the RPzB 54 Panzerschreck and the U.S. M9 bazooka, Corporal Donald E. Lewis of the U.S. Army informed his superiors that the Panzerschreck was "far superior to the American bazooka": ‘I was so favorably impressed [by the Panzerschreck] I was ready to take after the Krauts with their own weapon.’

The M1 bazooka fared much better on the rare occasions when it could be used against the much thinner armor typically fitted to the lower sides, underside, and top of enemy tanks. To hit the bottom panel of an enemy tank, the bazooka operator had to wait until the tank was surmounting a steep hill or other obstruction, while hitting the top armor usually necessitated firing the rocket from the upper story of a building or similar elevated position. During the 1944 Allied offensive in France — and most notably used during the Battle of Arracourt — Major Charles "Bazooka Charlie" Carpenter mounted a battery of three M9 bazookas on the wing-to-fuselage struts on each side of his L-4 Grasshopper aircraft in order to attack enemy armor, and was credited with destroying six enemy tanks, including two Tiger I heavy tanks.

Despite the introduction of the M9 bazooka with its more powerful rocket—the M6A3—in late 1943, reports of the weapon's effectiveness against enemy armor decreased alarmingly in the latter stages of World War II, as new German tanks with thicker and better-designed cast armor plate and armor skirts/spaced armor were introduced. This development forced bazooka operators to target less well-protected areas of the vehicle, such as the tracks, drive sprockets, bogey wheels, or rear engine compartment. In a letter dated May 20, 1944, Gen. 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." The extreme difficulty of closing to grenade-throwing distances unnoticed before hitting small spot targets on an enemy tank helps explain the high mortality rate of men assigned to anti-tank rocket launcher duty.

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 pill boxes. 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, most infantry 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 plate 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).

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 (90 mm) model was adopted, the M20 "Super Bazooka". Though bearing a superficial resemblance to the Panzerschreck, the M20 had greater effective range, 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 claimed 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.

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 US 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. During the initial stages of the Korean War, complaints resurfaced over the ineffectiveness of the 2.36-in M9 and M9A1 against Soviet-supplied enemy armor. In one notable incident, infantry blocking forces of the US Army's Task Force Smith were overrun by 33 North Korean T-34/85 tanks despite repeatedly firing 2.36 inch rockets into the rear engine compartments of the vehicles. Additionally, Ordnance authorities received numerous combat reports regarding the failure of the M6A3 warhead to properly detonate upon impact, eventually traced to inventories of rocket ammunition that had deteriorated from numerous years of storage in humid or salt air environments. Supplies of 3.5- in M20 launchers with M28A2 HEAT rocket ammunition were hurriedly airlifted from the United States to South Korea, where they proved very effective against the T-34 and other Soviet tanks. Large numbers of 2.36-inch Bazooka that were captured during the Chinese Civil War were also employed by the Chinese forces against the American Sherman and Patton tanks, and the Chinese later reverse engineered and produced a copy of the M20 designated the Type 51.

Vietnam War
The M20 "Super Bazooka" was used in the early stages of the war in Vietnam by the US Marines before gradually being phased out of in favor of the M67 recoilless rifle and later, the M72 LAW rocket. 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.

Other conflicts
Portuguese defense forces used quantities of M9A1 and M20 rocket launchers in their overseas departments in Africa against Marxist guerrilla forces during the Portuguese Colonial Wars. The French Army also used the M1A1, M9A1, and M20 launchers in various campaigns in Indochina and Algeria.

Rocket Launcher, M1 "Bazooka"

 * First issued June 14, 1942 by Capt. L.A. Skinner
 * Used the M6 rocket
 * Could penetrate up to 3 inches (76 mm) of armor.
 * Velocity of 265fps (80.77 m/s, 180 mph)

Rocket Launcher, M1A1 "Bazooka"

 * Improved electrical system
 * Simplified design
 * Used the M6A1 rocket
 * Forward hand grip deleted.
 * Contact box removed.

Rocket Launcher, M9 "Bazooka"

 * Optical reflector sight — the M9 and M9A1 featured the D7161556 folding "Reflecting Sight Assembly".
 * Reinforced launch tube
 * Metal Furniture
 * Used the improved M6A3 rocket
 * Could penetrate up to 4 inches (102 mm) of armor
 * Supplanted M1A1 in 1944
 * Could be disassembled into two halves for easier carrying.

Rocket Launcher, M9A1 "Bazooka"

 * Battery ignition replaced by trigger magneto.

Rocket Launcher, M18 "Bazooka"

 * Experimental
 * Aluminum alloy
 * Weight of 10.5 lbs
 * Ordered late summer 1945, canceled at war end.

Rocket Launcher, M20 "Super Bazooka"

 * Larger 3.5 in (90 mm) diameter warhead
 * Could penetrate up to 11 inches (280 mm) of armor
 * Extended range by about 150 m
 * Originally a larger version of the M9A1, designated M20 in late 1944.
 * Entered active service just before the start of the Korean War.

Rocket Launcher, M20B1 "Super Bazooka"

 * Lightweight version with barrels made of cast aluminum, other components simplified
 * Used as a supplement to the M20

Rocket Launcher, M20A1/A1B1 "Super Bazooka"

 * Product improved variant with improved connector latch assembly, entering production in 1952
 * Improved versions of the M20 and M20B1 respectively

Rocket Launcher, M25 "Three Shot Bazooka"

 * Experimental tripod mounted rocket launcher with overhead magazine circa 1955.

RL-83 Blindicide

 * RL-83 Blindicide an improved "Bazooka" design of Belgian origin. Used by Belgian forces during the Congo Crisis and by the Swiss Army, Mexican Army and Israeli Army and various other armed forces.

3.5 in HYDROAR M20A1B1 Rocket Launcher

 * Brazil, manufactured by Hydroar SA — improved 3.5 M20A1B1 with US designed hand grip magneto trigger replaced with one with solid state firing circuit powered by two AA batteries.

M65

 * Developed by Instalaza for use by the Spanish Army the M65 is an improved version of the M20 "Super Bazooka" which used an improved ignition method and new ammunition types.

M1

 * Length: 54 in (137 cm)
 * Caliber: 2.36 in (57 mm)
 * Weight: 13 lb (5.9 kg)
 * Warhead: M6 shaped charge (3.5 lb, 1.59 kg)
 * Range
 * Maximum: 400 yards (370 m)
 * Effective: (claimed) 150 yards (140 m)
 * Crew: 2, operator and loader

M1A1

 * Length: 54 in (137 cm)
 * Caliber: 2.36 in (57 mm)
 * Weight: 12.75 lb (5.8 kg)
 * Warhead: M6A1 shaped charge (3.5 lb, 1.59 kg)
 * Range
 * Maximum: 400 yards (370 m)
 * Effective: (claimed) 150 yards (140 m)
 * Crew: 2, operator and loader

M9/M9A1

 * Length: 61 in (155 cm)
 * Caliber: 2.36 in (57 mm)
 * Weight: 14.3 lb (6.5 kg)
 * Warhead: M6A3/C shaped charge (3.5 lb, 1.59 kg)
 * Range
 * Maximum: 400–500 yards (370–460 m)
 * Effective: (claimed) 120 yards (110 m)
 * Crew: 2, operator and loader (M9) or 1, operator+loader (M9A1)

M20A1/A1B1

 * Length (when assembled for firing): 60 in (1,524 mm)
 * Caliber: 3.5 in (90 mm)
 * Weight (unloaded): M20A1: 14.3 lb (6.5 kg); M20A1B1: 13 lb (5.9 kg)
 * Warhead: M28A2 HEAT (9 lb) or T127E3/M30 WP (8.96 lb)
 * Range
 * Maximum: 1000 yd (913 m)
 * Effective (stationary target/moving target): 300 yd (270 m) / 200 yd (180 m)
 * Crew: 2, operator and loader

Users
West Germany
 * 🇦🇷 Argentina: Super Bazooka, replaced by AT4
 * 🇦🇹 Austria: replaced by Carl Gustav recoilless rifle
 * 🇧🇷 Brazil
 * 🇧🇴 Bolivia HEAT and HE versions.
 * 🇰🇭 Cambodia
 * 🇨🇦 Canada
 * 🇨🇾 Cyprus
 * 🇫🇷 France
 * 🇬🇷 Greece
 * 🇮🇩 Indonesia
 * 🇮🇳 India
 * 🇯🇵 Japan: JGSDF used Super Bazooka, replaced by the Carl Gustav recoilless rifle
 * People's Republic of China: large numbers of 2.36-inch bazookas were captured by the Chinese Communists during the Chinese Civil War, and China also copied the 3.5-inch as the Type 51 — with a projectile 90mm in diameter. The Type 51 can fire captured 3.5-inch projectiles (i.e. 90 mm), but 3.5-inch Super Bazookas cannot load projectiles made for the Type 51.
 * Republic of China
 * Republic of Korea
 * 🇱🇺 Luxembourg
 * 🇲🇾 Malaysia
 * 🇲🇽 Mexico  replaced by M72 LAW
 * 🇲🇲 Myanmar
 * 🇵🇰 Pakistan
 * 🇵🇾 Paraguay
 * 🇵🇭 Philippines
 * 🇵🇹 Portugal
 * Rhodesia
 * 🇿🇦 South Africa
 * Soviet Union
 * 🇪🇸 Spain M65 - improved Spanish design.
 * 🇸🇪 Sweden: as Raketgevär 46, replaced by the Carl Gustav recoilless rifle
 * 🇹🇭 Thailand: as คจตถ. 3.5 นิ้ว in Royal Thai Army, replaced by Type 69 RPG
 * 🇹🇳 Tunisia
 * 🇹🇷 Turkey
 * 🇬🇧 United Kingdom
 * 🇺🇸 United States