Douglas A/B-26 Invader

Weapons and associated systems in detail

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Misc. weapons systems

M2 machine gun

The Browning .50 Caliber Machine Gun is a heavy machine gun designed towards the end of World War I by John Browning. It was nicknamed "Ma Deuce" by US troops or simply called "fifty-cal." in reference to its caliber. The design has had many specific designations; the official designation for the current infantry type is Browning Machine Gun, Cal. .50, M2, HB, Flexible. It is effective against infantry, unarmored or lightly-armored vehicles and boats, light fortifications, and low-flying aircraft.

The Browning .50 caliber machine gun has been used extensively as a vehicle weapon and for aircraft armament by the United States from the 1920s to the present day. It was heavily used during World War II, the Korean War, the Vietnam War, as well as during operations in Iraq in the 1990s and 2000s. It is the primary heavy machine gun of NATO countries, and has been used by many other countries. It is still in use today, with only a few modern improvements. The M2 has been in use longer than any other small arm in U.S. inventory. It was very similar in design to the smaller Browning Model 1919 machine gun.


A variant without a water jacket, but with a thicker-walled, air-cooled barrel superseded it (air-cooled barrels had already been used on variants for use on aircraft, but these quickly overheated in ground use). This new variant was then designated the M2 HB ("HB" for "Heavy Barrel"). The added mass and surface area of the new barrel compensated, somewhat, for the loss of water-cooling, while reducing bulk and weight (the M2 weighed convert|121|lb|abbr=on, with water, whereas the M2 HB weighs 84 lb). Due to the long procedure for changing the barrel, an improved system was developed called QCB (quick change barrel). A lightweight version, weighing 24 lb (11 kg) less—a mere 60 lb (27 kg)—was also developed

Design details

The M2 is a scaled-up version of John Browning's M1917 .30 caliber machine gun (even using the same timing gauges), fires the .50 BMG cartridge, which today is also used in high-powered sniper rifles and long range target rifles due to its excellent long range accuracy, external ballistics performance, incredible stopping power, and lethality. The M2 is an air-cooled, belt-fed, machine gun that fires from a closed bolt, operated on the short recoil principle. In this action, the bolt and barrel are initially locked together, and recoil upon firing. After a short distance, the bolt and barrel unlock, and the bolt continues to move rearwards relative to the barrel. This action opens the bolt, and pulls the belt of ammunition through the weapon, readying it to fire again, all at a cyclic rate of 450–600 rounds per minute (600–1,200 M2/M3 in WW2 aircraft, 300 synchronized M2). This is a rate of fire not generally achieved in use, as sustained fire at that rate will "shoot out" the barrel within a few thousand rounds, necessitating replacement. The M2 machine gun's sustained rate of fire is considered to be anything less than 40 rounds per minute.

The M2 has a maximum range of 7.4 kilometers (4.55 miles), with a maximum effective range of 1.8 kilometers (1.2 miles) when fired from the M3 tripod. In its ground-portable, crew-served role, the gun itself weighs in at a hefty 84 pounds (38 kg), and the assembled M3 tripod another 44 pounds (20 kg). In this configuration, the V-shaped "butterfly" trigger is located at the very rear of the weapon, with a "spade handle" hand-grip on either side of it and the bolt release the center. The "spade handles" are gripped and the butterfly trigger is depressed with one or both thumbs. When the bolt release is locked down by the bolt latch release lock on the buffer tube sleeve, the gun functions in fully automatic mode. Otherwise, the M2 is a single-shot weapon. Unlike virtually all other modern machine guns, it has no safety. Conversely, the bolt release can be unlocked into the up position resulting in single-shot firing (the gunner must press the bolt latch release to send the bolt forward). In either mode the gun is fired by pressing the butterfly triggers. Recently new rear buffer assemblies have used squeeze triggers mounted to the hand grips, doing away with the butterfly triggers.

Because the M2 was intentionally designed to be fit into many configurations, it can be adapted to feed from the left or right side of the weapon by exchanging the belt-holding pawls, the belt feed pawl, and the front and rear cartridge stops, then reversing the bolt switch. The conversion can be completed in under a minute with no tools.

There are several different types of ammunition used in the M2HB, including the current types: M33 Ball (706.7 grain) for personnel and light material targets, M17 tracer, M8 API (622.5 grain), M20 API-T (619 grain), and M962 SLAP-T. The latter ammunition along with the M903 SLAP (Saboted Light Armor Penetrator) round can penetrate up to 3/4 inch armor at 1500 meters. This is achieved by using a .30 inch diameter tungsten penetrator. The SLAP-T adds a tracer charge to the base of the ammunition. This ammunition was type classified in 1993.

When firing blanks, a large blank-firing adapter (BFA) must be used to keep the gas pressure high enough to allow the action to cycle. The adapter is very distinctive, attaching to the muzzle with three rods extending back to the base. The BFA can often be seen on M2s during peacetime operations.

Combat use The M2 .50 Browning machine gun has been used for various roles:

  • A medium infantry support weapon
  • As an anti-aircraft gun in some ships, or on the ground. The original water-cooled version of the M2 was used as an emplaced or vehicle-mounted anti-aircraft weapon on a sturdy pedestal mount. In some cases multiple air and water-cooled weapons were grouped. In some of these instances the mount featured one M2 with a left-handed feed and one with right-handed feed are paired.
  • Four and six guns are also sometimes mounted on the same turret.
  • Primary or secondary weapon on an armored fighting vehicle.
  • Primary or secondary weapon on a naval patrol boat.
  • Secondary weapon for anti-boat defense on large naval vessels (corvettes, frigates, destroyers, cruisers, etc).
  • Coaxial gun or independent mounting in some tanks.
  • Fixed-mounted primary armament in World War II-era U.S. aircraft such as the P-47 Thunderbolt, P-51 Mustang, and the Korean-era U.S. F-86 Sabre.
  • Fixed or flexible-mounted defensive armament in World War II-era bombers such as the A-26 Invader, B-17 Flying Fortress, and B-24 Liberator.

United States

At the outbreak of the Second World War the United States had versions of the M2 in service primarily as fixed aircraft guns and as anti-aircraft weapons (mounted on and off a wide variety of vehicles and ships). It was also technically still in service as an anti-tank weapon, as originally intended. On most of the vehicles the weapon was mounted on it was placed in a position designed for anti-aircraft rather than any other use. Units in the field often modified the mountings on their vehicles, especially tanks and tank destroyers, to be more useful in the anti-personnel role. Reports vary on its effectiveness in this role. There are instances of reports about the "essential" nature of the weapon for anti-personnel uses.

M2 variants

The basic M2 was deployed in US service in a number of subvariants, all with separate complete designations as per the US Army system. The basic designation as mentioned in the introduction is Browning Machine Gun, Cal. .50, M2, with others as described below.

The development of the M1921 water-cooled machine gun which led to the M2, meant that the initial M2s were in fact water-cooled. These weapons were designated Browning Machine Gun, Cal. .50, M2, Water-Cooled, Flexible. There was no fixed water-cooled version.

Improved air-cooled heavy barrel versions came in three subtypes. The basic infantry model, Browning Machine Gun, Cal. .50, M2, HB, Flexible, a fixed developed for use on the M6 Heavy Tank designated Browning Machine Gun, Cal. .50, M2, HB, Fixed, and a "turret type" whereby "Flexible" M2s were modified slightly for use in tank turrets. The subvariant designation Browning Machine Gun, Cal. .50, M2, HB, Turret was only used for manufacturing, supply, and administration identification and separation from flexible M2s.

A number of additional subvariants were developed after the end of the Second World War. The Caliber .50 Machine Gun, Browning, M2, Heavy Barrel, M48 Turret Type was developed for the commander's cupola on the M48 Patton tank, and then later used in the commander's position on the M1 Abrams tanks. Three subvariants were also developed for used by the US Navy on a variety of ships and watercraft. These included the Caliber .50 Machine Gun, Browning, M2, Heavy Barrel, Soft Mount (Navy) and the Caliber .50 Machine Gun, Browning, M2, Heavy Barrel, Fixed Type (Navy). The fixed types fire from a solenoid trigger and come in left or right hand feed variants for use on the Mk 56 Mod 0 dual mount and other mounts.

AN/M2, M3, XM296/M296, and GAU-10/A

The M2 machine gun was heavily used as a remote fired fixed weapon, primarily in aircraft, but also in other applications. For this a variant of the M2 was developed (sometimes seen under the designation AN/M2, but it is important to note that there were .30 and .50 caliber weapons with this designation), with the ability to fire from a solenoid trigger. For aircraft mounting some were also fitted with substantially lighter barrels, permitted by the cooling effect of air in the slip-stream. The official designation for this weapon was Browning Machine Gun, Aircraft, Cal. .50, M2 followed by either "Fixed" or Flexible" depending on whether the weapon was used as a fixed forward firing gun or for use by an airplane's crew.

Name - Browning Machine Gun, Cal. .50, M2, HB
Type - Heavy machine gun
Origin - United States

Era - Post-WW1
Platform - Tripod, vehicle
Target - Personnel, light-armored vehicles, aircraft
Design date - 1918
Production date - 1933–present (M2HB)
Service - 1921

M2HB from 1933–present
Wars - World War II, Korean War, Vietnam War, Cambodian Civil War, Falklands War, Desert Storm, Somali Civil War, Iraqi Freedom, Operation Enduring Freedom, South African Border War

Weight - 38 kg (84 lb), 58 kg (128 lb) with tripod and T&E
Length - 1650 mm (65 in)
Part length - 1143 mm (45 in)
Cartridge - .50 BMG
Action - Short recoil-operated
Rate - 450–600 rnds/min (M2HB) 750–850 rnds/min (M2 aircraft gun)
Velocity - 2,910 feet per second (M33 Ball) (887.1 m/s)
Max range (updated USMC standard) - 6767 meters / 7400 yards; Max Effective Range - 1830 m (area target), 1500 m (point target) & 700 m (grazing fire)
Feed - Belt-fed







XA-26B ( 41-19588 )

Work on the A-26 seems to have been triggered by a letter sent to Douglas on 5 November 1940 by Major Frank O. Caroll, chief of the Air Corps' Experimental Engineering Section at Wright Field, possibly in the aftermath of a visit to the base by Edward H. Heinemann, a senior Douglas designer. The letter gave a list of those features of the Douglas A-20 that the Air Force thought needed to be improved in a new bomber. The A-20 was considered to have five main faults

After his trip to Wright Field Heinemann, who was the designer and patent holder for the A-20, began to work on a design for a bomber capable of carrying a 75mm cannon. At the same time R.G Smith, an engineer and artist, and Arthur Raymond, the engineering vice president of Douglas, began to work on the same project.

On 2 June 1941 Douglas was given contract W535 ac-17946, for one XA-26 bomber and one XA-26A night fighter, at a price of just over two million dollars. Later in June a third prototype, the XA-26B armed with a 75mm cannon, was added to the order, and by the end of October 1941, well before the maiden flight of the prototype, Douglas received a contract for the first 500 A-26s.

The Army Air Force's inability to decide exactly how they wanted the A-26 to be armed also caused some delays. In the summer of 1942 they decided that the first 500 aircraft would carry the 75mm cannon, and also ordered 200 gun noses carrying six .50in machine guns, which could be installed in the field. A series of experiments were carried out with different combinations of guns, using 75mm, 37mm and 20mm cannon and .50in machine guns. On 17 March 1943, when a second contract was issued for 500 more aircraft, the 75mm cannon was still in favour, but eventually only the XA-26B prototype would carry the big gun, and the .50in machine gun nose became the standard for the A-26B.

The third prototype, the XA-26B (serial number 41-19588) was added to the program just after the first two, carried a crew of three and was armed with a solid nose that could carry a wide number of different guns, from .50in machine guns up to a massive 75mm cannon. The XA-26B was the only aircraft to carry the 75mm gun, on the right side of the nose and protected by a retractable cover. The same 75mm gun was installed on the B-25 Mitchell, and proved to be disappointing in service, partly because of its slow rate of fire and partly because suitable targets were often rare.

Prototype ground-attack version, solid nose with
75mm cannon.
Produced 1942










The 5-inch FFAR suffered from insufficient speed because of its small motor. Therefore the development of a larger rocket motor with 5-inch diameter was begun, and the first test firings occurred in December 1943. When fitted with the warhead of the 5-inch FFAR, the rocket achieved a velocity of 1530 km/h (950 mph), making it a very powerful weapon for its time. It was officially designated as 5-Inch HVAR (High-Velocity Aircraft Rocket), but often called Holy Moses. It became operational in July 1944, and was used by Army Air Force and Navy aircraft.




Above, Under the wing is a 750lb napalm bomb and four 6.5" rockets.


The Mk 4 Folding-Fin Aerial Rocket (FFAR), sometimes called the Mighty Mouse, was a 2.75 in (70 mm) diameter unguided rocket weapon commonly used by U.S. military aircraft. It was intended as an air-to-air weapon to allow interceptor aircraft to shoot down enemy bombers with greater range and effectiveness than machine guns or cannon. It was later developed into a modular rocket motor for air-to-ground use.

The United States was the primary user of this type of weapon and developed a number of different launching pods for it. Initially pods were intended to be disposed of by launching aircraft, either in flight or on the ground following a mission. With the advent of the armed helicopter, the need for launching pods that were reusable became apparent. Though the rocket was initially developed by the US Navy, the US Air Force and later US Army were most responsible for the development of rocket pods for all services.

LAU-32/A 7-Tube 70 mm (2.75”) rocket launcher

Length: 4 feet 0 inches
2.75 inches
Weight: 18.5 lbs
Max Speed:
Range: 3,700yds
Guidance: Unguided
6lbs High Explosive Fragmentation
First Flight : 1949



The Mk 77 Mod 4 fire bomb holds approximately 75 gallons of fuel gel mixture and weighs approximately 500 pounds when filled.

The container is cigar-shaped, non-stabilized (will tumble end over end when released from the aircraft), lightweight, and is made of aluminum. It has a 14-inch suspension between the lugs and provides two filler holes, which are 31 degrees down from the top of the container. The filler holes are covered by filler caps, which are secured by retainer rings. The filler caps prevent foreign objects from getting inside the container during shipping and storage, and provides a sealed closure after the container is filled with fuel gel before fuzing. The filler holes also provide for the installation of the primary fuses. During fuzing procedures, the filler caps are removed and replaced by igniters, which seals the closure.

The primary fuzing system consists of the igniter Mk 273 Mod 0 with the M918 fuze or the initiator Mk 13 (igniter Mk 273 Mod 1 with the Mk 343 fuze). The Mk 77 Mod 4 also has provisions in the nose and tail for an alternate fuzing system using the AN-M173A1 fuze and AN-M23A1 igniter.

Functional Description
When the fire bomb is released from the aircraft, the arming wires are pulled from the fuzes, allowing the fuzes to become armed. When the bomb impacts the target or the ground, the container will rupture, disbursing the fuel gel mixture over the area. The fuzes detonate, rupturing the igniters, which , in turn, ignites the gel mixture.

Fuel Gel Mixture
Fire bomb fuel gel mixture, formerly called napalm, is a mixture of fuel and gelling
solution that produces a thickened mixture. The gel should be stringy and sticky and readily adhere to most surfaces. The fuel gelling system consists of a fuel gelling unit, drums of gelling solution, aviation gas, mogas, JP-4, or JP-5 fuels.


1. Introduction

a. The droppable auxiliary aircraft fuel tank can be readily converted into an incendiary munition.

b. It is an effective weapon for use against personnel occupying gun emplacements, pill boxes, embrasures, caves, fox holes or truck convoys. Any material which is in part or entirely combustible, such as bridges, docks, railroad trestles, wooden surface vessels, small craft, warehouses and supply dumps make suitable targets for the Fire Bomb.

2. Preparation of Fire Bomb

a. To convert the gasoline tank into a Fire Bomb required only replacement of the standard filling cap with an E4R1 igniter.

b. If two igniters per bomb are desired an E3R1 igniter may be attached to the tail plug.

3. Fire Bomb Filling

a. Fuel may be a mixture of Napalm and any gasoline available.

b. A 6.1 percent by weight of Napalm (Eakins) In the gasoline-Napalm mix is recommended. At installations where other brands of Napalm are supplied, a sample mix should be made before the initial Fire Bombs are filled.

c. Time required for mixing of the solution varies with gasoline temperature, type of Napalm used, and the amount of air agitation.

(1) Gasoline temperature range for rapid mixing is from 70 Fahrenheit to 90 Fahrenheit.

(2) Mix depicted hereafter was made at 72 Fahrenheit using Eakins Napalm and required 4 to 5 minutes agitation per drum to gel.

d. After mix has gelled (tapioca stage) it should “cure” for at least 4 hours before using. This period of curing is necessary to permit the Napalm and gasoline to become a homogeneous mixture.

e. Once mixed the fuel may be left in the drums for extended periods without “breaking down” occurring.

4. Transferring fuel from Drum to Fire Bomb

a. Minimum pressure should be that which satisfactorily moves fuel from the drum into the Fire Bomb. This practice reduces the danger of bursting the drum. Pressure of 15 pounds per square inch was found sufficient to empty a drum through approximately 14 feet of hose and the quick opening valve into the Fire Bomb In 6 minutes.

5. Employment of the Fire Bomb

a. Reports from the field state that aircraft carrying the Fire Bombs prefer to come in at low altitudes (50 to 100 feet) and release the bombs in front of the objective, thereby throwing the contents forward onto the target.

b. Normally one bomb is released at a time as the area coverage is not markedly increased when both bombs are released simultaneously.

(1) Area coverage from one bomb is approximately 100 feet by 300 feet. The longitudinal axis being parallel to the line of flight.



The bomb bay showing 2 M31 and M32 thermite incendiary clusters "Funny Bombs" and frag bomb clusters

SSU-14/A Submunition dispenser

The SUU-14/A resembled a bundle of six pipes strapped together, with a cap on the front end to hold them together. It ejected the submunitions out the rear. The photographic record suggests that it was particularly popular. Configurations for the SUU-14/A included:

  • CBU-14/A: BLU-3/B Pineapple bomblets, quantity unknown.

  • CBU-22/A: 72 BLU-17/B white phosphorus smoke bomblets.

  • CBU-25/A: 132 "BLU-24/B Orange" antipersonnel fragmentation bomblets. The BLU-24/B did in fact look very much like an orange, sitting on a cylindrical base. It weighed 540 grams (1.2 pounds) and could throw out 300 steel fragments.

  • CBU-57/A: 132 "BLU-57/A"

Some sources mention that the SUU-14/A also carried a minelet known as "gravel" in Vietnam. It was apparently nothing but a small lump of plastic explosive that was packed in a freon-filled container and became very shock-sensitive when it dried after dispersal. Details are very unclear, with pictures available showing a wedge-shaped cloth packet designated "XM27", or square cloth packets with the designation "XM40", "XM41", "XM44", or "XM65".

Cluster submunition dispensers were often used in Vietnam by search and rescue support aircraft, such the Douglas A-1 Skyraider. Riot gas loads were useful for interfering with the work of antiaircraft gunners, and a Skyraider could lay down a carpet of minelets behind downed aircrew on the run to block pursuers.


"Rockeye" Cluster Bomb

The CBU Mark 20 Rockeye II was an antitank cluster bomb that dispensed 247 shaped-charge bomblets. This unguided free-fall weapon was developed by the U.S. Naval Weapons Center in 1963 and was produced in 1967. Weighing close to 500 pounds, the CBU Mark 20 was delivered by aircraft to the target area and upon release opened to expel anti-tank bomblets that could destroy a number of targets on the ground simultaneously.



Clarification by Jim Rotramel, from Maryland
The BLU-69/B was a 1.6-pound, 2.765-inch diameter incendiary bomb manufactured by Ordnance Research Inc. of Fort Walton Beach, Florida. A modification of the BLU-24 design, it had an incendiary case made of cerium alloy, metal powder, and plastic binder. The bomb would spin arm after being ejected from the dispenser. Its modified M219 fuze would function on impact, causing a first fire charge type boron potassium nitrate pellet to detonate, igniting the case, which would then explosively eject hot particles at random times. The CBU-57 was a SUU-14A/A dispenser with 132 BLU-69/B.

I don't have any information of the BLU-57 other that it, the BLU-58 (and possibly the BLU-56) were all assigned designations on 29 Aug 67. (BTW, they would have been "/B" designations, as '/A" means it's something retained on the aircraft to preform its intended function. It's possible that these were re-designations of the gravel mines. My research indicates that the primary/only dispensers used to deploy the gravel mines was the SUU-41 series dispenser, used by F-4s and XM3 dispensers used by A-1s.
I don't have any information indicating these weapons were ever used by A-26As.


Jim Rotramel

MK 82 ( Non Guided ) Bomb

The Mark 82 (Mk 82) is an unguided, low-drag general-purpose bomb (unguided bomb), part of the U.S. Mark 80 series. The explosive filling is tritonal.

Development and deployment

With a nominal weight of 500 lb (227 kg), it is the smallest of those bombs in current service, and one of the most common air-dropped weapons in the world. Although the Mk 82's nominal weight is 500 lb (227 kg), its actual weight varies considerably depending on its configuration, from 510 lb (232 kg) to 570 lb (259 kg). It is a streamlined steel casing containing 192 lb (89 kg) of Tritonal high explosive. The Mk 82 is offered with a variety of fin kits, fuzes, and retarders for different purposes.

The Mk 82 is the warhead for the GBU-12 laser-guided bombs and for the GBU-38 JDAM.

Currently only the General Dynamics plant in Garland, Texas is DoD certified to manufacture bombs for the US Armed Forces.

The Mk 82 is currently undergoing a minor redesign to allow it to meet the insensitive munitions requirements set by Congress.

According to a test report conducted by the United States Navy's Weapon System Explosives Safety Review Board (WSESRB) established in the wake of the tragic 1967 USS Forrestal fire, the cooking off time for a Mk 82 is approximately 2 minutes 30 seconds.

More than 4,500 GBU-12/Mk 82 laser guided bombs were dropped on Iraq during the Persian Gulf War.

Low-level delivery

In low-level bombing, it is easy for the delivering aircraft to sustain damage from the blast and fragmentation effects of its own munitions because the aircraft and ordnance arrive at the target at the same time. To combat this, the standard Mk-82 General Purpose bomb can be fitted with a special high-drag tail fin unit. In this configuration, it is referred to as the Mk-82 Snakeye.

The tail unit has 4 folded fins which spring open into a cruciform shape when the bomb is released. The fins increase the drag of the bomb, slowing its forward progress and allowing the delivery aircraft to safely pass over the target before the bomb explodes.


  • BLU-111/B – Mk 82 loaded with PBXN-109 (vs H-6); item weighs 480 lbs. PBXN-109 is a less sensitive explosive filler. The BLU-111/B also is the warhead of the A-1 version of the Joint Stand-Off Weapon JSOW.
  • BLU-111A/B – Used by the U.S. Navy, this is the BLU-111/B with a thermal-protective coating added to reduce cook-off in (fuel-related) fires.
  • BLU-126/B – Designed following a U.S. Navy request to lower collateral damage in air strikes. Delivery of this type will start no later than March 2007. Also known as the Low Collateral Damage Bomb (LCDB), it is a BLU-111 with a smaller explosive charge. Non-explosive filler is added to retain the weight of the BLU-111 so as to give it the same trajectory when dropped.
  • Mark 62 Quickstrike mine – A naval mine, which is a conversion of Mark 82 bomb.



The Mk 82 and the Daisy Cutter

A daisy cutter is a type of fuse designed to detonate an aerial bomb at or above ground level. The fuse itself is a long probe affixed to the weapon's nose, which detonates the bomb if it touches the ground or any solid object.

The purpose for a daisy-cutter fuse is primarily to maximize blast damage on the surface of a target. A bomb with a conventional fuse will often be driven deeply into the ground by the force of its impact, limiting the range of its blast. A bomb with a daisy-cutter fuse will detonate before it has a chance to penetrate the ground, allowing its energy to spread over a larger area. For this reason daisy-cutter fuses are often used to clear foliage and vegetation, such as for the purpose of creating Landing Zones for helicopters.

The first reference to a "daisy-cutter type of bomb" is found in the memoir of Lieutenant Jack Wilkinson in describing the 1918 attack on the Royal Air Force airfield at Bertangles. Wilkinson describes it as a "bomb that seemed to explode before it buried itself in the ground so that bits and pieces flew horizontally in all directions."

Oskar Dinort invented an extended-nose fuse device known as the Dinort-Stab device. These were placed on the noses of German World War II-era bombs up to 250 kg (550 lb) in mass, such as the SC 50 and 250 bombs dropped from Junkers Ju 87 (Stuka) dive bombers.

"Daisy cutter" fuses, when known under that exact name, were first used by the United States during the Vietnam War. The concept for the fuse is attributed to an Air America employee who grasped the idea during a night of drinking. Shortly thereafter, his drinking buddy, a Royal Lao Air Force airman at Louang Phrabang, gathered the needed materials for the prototype and started welding used aircraft gun barrels directly into the nose fuse cavity of bombs. After the concept proved itself useful was made famous by being used for the largest conventional bomb in the U.S. military's arsenal at the time, the BLU-82. When used gun barrels were in short supply, water pipes were requisitioned for the task. The welded pipe versions had several adverse effects, such as vibration, pipe weld separation or breakage while in flight, and wind drag, due to impossibility of aligning the pipes correctly with the nose of the weapon, so that phase of development eventually gave way to threaded steel water pipes screwed into the nose cavity of the bombs, leaving only the tail fuse for detonation. After the war more precise fuses were created for this purpose.

These weapons were used in the "shock and awe" phase of the Iraq War, but on a much bigger scale and dropped from a C-130.