Staff Writer (Updated: 4/6/2016):
The Bazooka Name
The "Bazooka" nickname stems from its resemblance to the trombone-like wind instrument developed by radio comedian Bob Burns. Burns used the instrument in his skits and copyrighted the design as early as 1920 and, for whatever reason, granted it the name "Bazooka". When Brigadier General Gladeon M. Barnes of the Ordnance Department saw the weapon, he commented on how the weapon resembled Burns' "Bazooka" and this nickname was, unofficially and forever, attached to the M1 weapon and subsequent developments. The weapon was also known by troops in its shortened "Zooka" nickname form or simply called the "stovepipe" for its obvious resemblance to a stove's exhaust stack. "Shoulder 75" was a lesser-used term which likened the firepower of the simple little M1 to that of a larger 75mm artillery piece.
Prior to World War 2, armies of the world embraced several anti-tank measures such as awkward, small-caliber towed guns, long, heavy and cumbersome anti-tank rifle and infantry-level grenades of various designs. Towed guns required tow vehicles or mover animals and were not very mobile. Anti-tank rifles were nothing more than oversized service rifles which were heavy in practice and expensive to manufacture necessary numbers. Infantry-level anti-tank grenades required personnel to be dangerously close to approaching tanks when used and the results of such weapons were usually mixed in their execution.
In September of 1939, Germany invaded Poland, officially beginning World War 2. Germany's skillful use of armor, infantry and aircraft led to Poland's quick demise in which The Low Countries and France soon followed. As German tank armor strength continued to grow heading into 1940, many of the existing anti-tank weapons were quickly becoming obsolete though sheer desperation forced their continued presence as frontline implements. The most common towed anti-tank gun caliber was the 37mm and these proved effective against light-armored vehicles. Their caliber size allowed them to be modestly portable as well, though still not effective in a fluid battle. Armies then moved beyond light tanks and introduced medium tank models which improved armor protection and primary gun strength.
The US Army had let their opportunity for casual anti-tank weaponry improvement slip by before the time of World War 2 in Europe. Its primary anti-tank weapon was the 37mm M3 towed anti-tank gun which suffered from the aforementioned limitations of other 37mm field systems early in the war. To make matters more difficult, the Americans had elected not to adopt an anti-tank rifle unlike the Germans, British and Soviets. What value the armor-piercing ammunition the Browning 0.50 caliber machine gun had was lost as increased armor combat vehicles began to appear in Europe.
Work on battlefield rocketry was being undertaken in America as early as 1933 at the storied Aberdeen Proving Ground under the Ordnance Department's "Rocket Branch". The division was headed Captain Leslie Skinner who had privately engineered rockets for decades prior. At this point in history, American Army authorities held little interest in sinking money and resources into an effective battlefield anti-tank rocket; that was until the results of the German advances of 1939-1940 alerted leaders to their need. Studies were initially held with British-originated naval anti-aircraft rockets and launchers, which the American program evolved into a portable launcher in the 20lb range that fired an effective, rocket-propelled penetrator while also providing little to no recoil.
Swiss Army gunner Henry Mohaupt developed the 2.36" M10 "High-Explosive, Anti-Tank" (HEAT) "spigot" shaped-charge grenade that was shown to US Army authorities who, in 1940, had little interest. After testing by the Ordnance Department proved it held sound penetration capabilities, just the munition was adopted as the M6. Skinner continued development of a shoulder-mounted launcher unit, still convinced of its battlefield merits, while the M6 grenade evolved along its own lines. Skinner was then joined in his exploits by 2nd Lieutenant Edward Uhl and the two finalized an improved launcher and rocket which was successfully test-fired. When pressed into a formal evaluation of their design at Aberdeen Proving Ground, the weapon exhibited excellent results against five competing "spigot" mortar designs, all of which managed to miss their target - a moving tank.
The United States officially entered World War 2 shortly after the Japanese surprise attack at Pearl Harbor on December 7th, 1941. The American declaration followed and war industry mobilized for overseas combat. All manner of weapons systems were then adopted including the Skinner design as the 2.36" T1 in prototype form. The production contract was handed to General Electric (Bridgeport) on May 20th, 1942 and the weapon was formally designated as the 2.36" Rocket Launcher M1. The finalized product included improved sights, a revised action and a shortened launcher body. The grenade (designated "M6 HEAT") joined production under the E.G. Budd Company brand label.
Design of the Bazooka was fairly straight forward, incorporating a simple launch tube body, integrated sights for aiming, a protected internal power supply, a rudimentary shoulder support structure and pistol- grip assembly which held the trigger unit. The tube was open at the breech and the muzzle for the loading and exiting of the rocket projectile which was electrically-actuated by way of a battery pack found in the base of the shoulder support. The grip and shoulder support were made of wood and electrical components were held in a small box fitted atop the launch unit body. A red light was situated at the power box positive contact and illuminated when the trigger was squeezed. A guard was affixed to the muzzle to deflect any still-burning propellant from the firer's face and hands.
Initial M1 production models incorporated a forward grip ahead of the standard pistol grip though these were eventually discarded when it was found they provided little support value. Sights were also originally intended to make the M1 ambidextrous in its usage, but ultimately it was relegated to favor right-handed shooters in the end. Interestingly, first forms did not incorporate shoulder strap sling loops for transport forcing infantry to devise home-made straps for a time. A seldom-used bipod was also part of the original M1 design though its added weight and nonadjustable nature led to it be discarded in the field.
Construction of the M1 was simple, allowing for low-cost serial production in the numbers required. The system was also very portable despite its length and easy to operate between the two required crew - one to load the weapon and the other to fire. Original sights allowed for ranging between 100 and 400 yards and a safety mechanism allowed for a safe and active fire mode. The weapon would automatically set itself to safe upon a rocket projectile having been fired.
The 2.36" Launcher Family - M1, M9 and M18
The 2.36 launcher appeared in four major forms during the Bazooka's active service life: the M1, M1A1, M9/M9A1 and M18. Performance of the M1 and M1A1 was nearly indestinquishable. The M9/M9A1 was heavier than the M1/M1A1 model by nearly 3lbs (13.1lbs versus 15.87lbs) and featured a longer running length of 61 inches (versus 54.5 inches), which improved effective engagement ranges from 250 yards to 300 yards. It also allowed for a rate-of-fire increase of 10 rounds per minute (compared to the 5rpm limit of the M1/M1A1 models). The later M18was the lightest form of them all at 10.3 lbs. Its length was slightly reduced from that of the M9 family to 60.5 inches while engagement ranges were the same as well as its listed rate-of-fire.
Of note is the much improved portability of the M9/M9A1 and the M18 as both were able to be broken down into two major sections. This proved very effective for airborne units who often dealt in space-strapped conditions aboard transport aircraft. Being able to land with an anti-tank capability broadened the tactical value of the paratrooper considerably.
The 3.5" Launcher Family - M20 and M25
The original M20 launcher weighed 15lbs and featured a running length of 60.25 inches. Broken down, the launcher was a handier 33 inch length. Effective range was listed out to 300 yards with a rate-of-fire nearing 4 rounds per minute. The M20B1 followed these same qualities save for its 14lb operating weight. The M20A1 sported a weight of 13lbs, a 60 inch length and a 6 round-per-minute rate-of-fire. The M20B1 and M20A1B1 utilized different construction techniques. The seldom-overlooked M25 model was a repeat-firing Bazooka fitted atop a tripod. The weapon was fed by a three-round magazine cassette on top of the breech while other qualities of the launcher were shared with the M20 family. This system weighed 100lbs (60lbs for the launcher, 40lbs for the tripod), sported a 68.5 inch length and 350 yard reach. Unlike other M20 models, the M25 broke down into a 39.5 inch length and featured a rate-of-fire of up to 10 rounds per minute.
The Bazooka Firing Process
The full action of the Bazooka required the two operators to work in unison. The firer set the launcher upon his shoulder and usually took on a kneeling position with the weapons safety activated at this point. The loader inserted a rocket projectile into the breech end and removed the projectile's arming pin. The projectile was then inserted fully into the breech until locked in place by an awaiting latch. A coiled wire was then unfurled from the rocket's fin assembly and wrapped around a contact spring found on the launcher. At this point, the loader communicated a ready signal to the firer and the firer was ready to make his decision. He (and those around him) did have to take special care when firing to make sure that the back-blast of the open breech end did not endanger any nearby allies.