Lực lượng phòng vệ Nhật Bản - 日本国自衛隊 - The Japan Self Defence Forces P2

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Súng Máy 12.7 MM-M2
Type Heavy machine gun
Place of origin United States
Service history
In service 1921
M2HB from 1923?"present
Used by United States, and several others
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
Production history
Designed 1918[1]
Produced 1933?"present (M2HB)
Specifications
Weight 38 kg (84 lb), 58 kg (128 lb) with tripod and T&E
Length 1650 mm (65 in)
Barrel length 1143 mm (45 in)
Cartridge .50 BMG
Action Short recoil-operated
Rate of fire 450-575 rounds/min (M2HB)
750?"850 rounds/min (AN/M2)
1,200 rounds/min (AN/M3)
Muzzle velocity 2,910 feet per second (M33 Ball) (887.1 m/s)
Feed system Belt-fed (M2 or M9 links)
en.wikipedia.org

Được alphandt sửa chữa / chuyển vào 12:49 ngày 15/06/2009
Được alphandt sửa chữa / chuyển vào 13:02 ngày 15/06/2009

The M2 Machine Gun, Browning .50 Caliber Machine Gun, or "Ma Deuce" is a heavy machine gun designed towards the end of World War I by John Browning. It was nicknamed Ma Deuce by U.S. Military personnel 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 as well. 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. The M2 is currently manufactured by General Dynamics and FNH for the United States government. FNH has been the manufacturer since John Browning worked for them in the 1910s and ''20s to develop the machine gun.[2]
en.wikipedia.org

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 long range accuracy, external ballistics performance, 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.
The M2 has varying cyclic rates of fire, depending upon the model. The M2HB (heavy barrel) air-cooled ground gun has a cyclic rate of 450-575 rounds per minute.[4] The early M2 water-cooled AA guns had a cyclic rate of around 450-600 rpm.[5] The AN/M2 aircraft gun has a cyclic rate of 750-850 rpm; this increases to 1,200 rpm or more for AN/M3 aircraft guns fitted with electric or mechanical feed boost mechanisms.[6] These maximum rates of fire are generally not achieved in use, as sustained fire at that rate will wear out the bore within a few thousand rounds, necessitating replacement. The M2HB''s sustained rate of fire is considered to be anything less than 400 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 as the M2HB, 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. Recently new rear buffer assemblies have used squeeze triggers mounted to the hand grips, doing away with the butterfly triggers.
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. 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). Unlike virtually all other modern machine guns, it has no safety (although a sliding safety switch has recently been fielded to USMC armorers for installation on their weapons). Troops in the field have been known to add an improvised safety measure against accidental firing by slipping an expended shell casing under the butterfly trigger.[7]
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 and AN aircraft guns. From World War II through the Vietnam War, the big Browning was used with standard ball, armor-piercing (AP), armor-piercing incendiary (API), and armor-piercing incendiary tracer (APIT) rounds. All .50 ammunition designated "armor-piercing" was required to completely perforate 0.875" (22.2 mm) of hardened steel armor plate at a distance of 100 yards (91 m), and 0.75" (19 mm) at 547 yards (500 m).[8] The API and APIT rounds left a flash, report, and smoke on contact, useful in detecting strikes on enemy targets; they were primarily intended to incapacitate thin-skinned and lightly armored vehicles and aircraft, while igniting their fuel tanks.[9]
Current ammunition types include: 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 perforate 1.34 in (34 mm) of HHA (high hard armor, or face-hardened steel plate) at 500 meters, 0.91 in (23 mm) at 1,200 meters, and 0.75 in (19 mm) at 1,500 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.[10][11]
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.
en.wikipedia.org

Súng Máy 20MM-JM61