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jacket, but with a thicker-walled, air-cooled barrel superseded it (air-cooled barrels had already been used on variants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
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.
The M2 .50 Browning machine gun has been used for various
A medium infantry support
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.
armament in World War II-era U.S. aircraft such as the P-47 Thunderbolt, P-51 Mustang, and the Korean-era U.S.
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.
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.
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.
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
- Heavy machine gun
Origin - United States
Era - Post-WW1
- Tripod, vehicle
Target - Personnel, light-armored vehicles, aircraft
date - 1918
Production date - 1933–present (M2HB)
M2HB from 1933–present
- 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
- 38 kg (84 lb), 58 kg (128 lb) with tripod and T&E
Length - 1650 mm (65 in)
length - 1143 mm (45 in)
Cartridge - .50 BMG
Rate - 450–600 rnds/min (M2HB) 750–850 rnds/min (M2
Velocity - 2,910 feet per second (M33 Ball) (887.1 m/s)
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
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
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
Above, Under the wing is a 750lb napalm bomb and four
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
Weight: 18.5 lbs
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.
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
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.
The droppable auxiliary aircraft fuel tank can be readily converted into an incendiary munition.
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.
of Fire Bomb
To convert the gasoline tank into a Fire Bomb required only replacement of the standard filling cap with an E4R1 igniter.
If two igniters per bomb are desired an E3R1 igniter may be attached to the tail plug.
Fuel may be a mixture of Napalm and any gasoline available.
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.
Time required for mixing of the solution varies with gasoline temperature, type of Napalm used, and the amount of air
Gasoline temperature range for rapid mixing is from 70° Fahrenheit to 90° Fahrenheit.
Mix depicted hereafter was made at 72° Fahrenheit using Eakins Napalm and required 4 to 5 minutes agitation per drum
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.
Once mixed the fuel may be left in the drums for extended periods without “breaking down” occurring.
fuel from Drum to Fire Bomb
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.
of the Fire Bomb
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.
Normally one bomb is released at a time as the area coverage is not markedly increased when both bombs are released simultaneously.
Area coverage from one bomb is approximately 100 feet by 300 feet. The longitudinal axis being parallel to the line of
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",
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
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.
by Jim Rotramel, from Maryland
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.
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
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.
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-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.
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.