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Sigma KEE - HeavyMachineGun
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heavy machine gun
A heavy machine gun refers to either a larger-caliber, high-power machine gun or one of the smaller, medium-caliber (rifle caliber) machine guns meant for prolonged firing from heavy mounts, less mobile, or static positions (or some combination of the two). The latter meaning is generally thought of as an older meaning, and the former as a modern one, but both weapon types have histories extending back to the 1800s. Furthermore, heavier smaller-caliber weapons continue to be used up to the present. A classic example of a rifle-caliber heavy machine gun would be a water-cooled Maxim machine gun that was belt fed, had a water jacket, was crew served, and mounted on tripod or wheeled mount. Other types used linkable strips (such as the Hotchkiss) or large magazines. A common example of a heavy-caliber machine gun would be the Browning M2 .50-caliber machine gun. Firearms with calibers larger than 13 to 15 mm are generally thought of as autocannons instead of heavy machine guns. (from Wikipedia)
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Parents automatic gun A Gun that fires a burst of Projectiles with each pull of the trigger. Also known as a machine gun.
Children chain gunA chain gun is a type of machine gun or automatic cannon that uses an external source of power, rather than recoil, to cycle the weapon, and does so via a continuous loop of chain similar to that used on a motor or bicycle. Chain gun is a registered trademark of McDonnell Douglas for a chain-powered weapon. The primary advantages of chain-driven weapons over their recoil-actuated counterparts are their reliability and controllability. Rather than being dependent upon recoil to actuate the system, which is usually derived from the detonation of a cartridge and is thus inherently uncontrollable, a chain gun instead depends on an external motor to produce power. The motor drives the chain, the chain moves in a rectangular loop via four sprockets which tension it, and one link of the chain is in turn connected to the bolt assembly, thus the bolt moves back and forth to load, fire, extract and eject cartridges. As with other externally-powered guns, this provides a degree of reliability. In addition, and again as with all externally-controlled guns, a misfired round does not stop the weapon - it is simply ejected. The speed of the motor also controls how fast the weapon fires, and thus provides controllability. During each full cycle of the chain link attached to the bolt assembly, two periods (passage along the 'long' sides of the rectangle') control the time taken for the bolt to drive forward and chamber a round and how quickly it extracts it, whilst the other two periods - when the chain moves across the 'short' sides of the rectangle, sideways relative to the axis of the barrel - determine for how long the breech remains locked (during firing) and open (allowing extraction and ventilation of fumes etc). Since it is the time taken for the chain to move around a complete loop of the rectangle that controls the rate of fire of the gun, chain guns can theoretically operate at an infinite number of firing rates from single shot to the maximum imposed by mechanical etc tolerances. In practice, chain guns come with two or three pre-set firing speeds. (from Wikipedia)
 grenade launcherA grenade launcher is an machine gun able to shoot grenades at high frequency.
 M2 Browning machine gunThe M2 Machine Gun, or Browning .50 Caliber Machine Gun is a heavy machine gun designed just after World War I by John Browning. It is nicknamed Ma Deuce by US troops or simply called fifty caliber machine gun. The design has had many specific designations- the official designation for the infantry type is Browning Machine Gun, Heavy Barrel, Cal. .50, M2, HB, Flexible. The Browning .50 machine gun was 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, Korean War, the Vietnam Conflict, 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. It was very similar in design to the smaller Browning Model 1919 machine gun .30-06 Springfield. Type Fully-automatic machine gun Caliber .50 in (12.7 mm) Ammunition .50 BMG Feed system Belt-fed Action Recoil-operated, short recoil Length 1,650 mm (65 in) Barrel length 1,140 mm (44 7/8 in) Weight 38 kg (58 kg w/ tripod) Rate of fire 550 round/min Muzzle velocity 3,050 ft/s (930 m/s) Effective range 2,000 m (2200 yards) (from Wikipedia)
 M3M machine gunThe M3M is a weapon system rather than just a machine gun. The system has three parts: The Machine Gun, the Medium Pintle Head (MPH) or Soft Mount, and the Cradle, which is used to integrate the weapon into a particular aircraft or vehicle. An optional Integrated Illuminator/Laser spotting device gives this weapon a day/night capability. Three important differences between the M3M and the M2 BMG: 1) The new weapon uses an open bolt 2) has an internal recoil spring, and 3) a significantly longer barrel life. The first difference means that cook-offs are far less likely to occur while the second point means that the M3M has only a third as much non-compensated recoil as compared to the M2 BMG. As a personal note, I have been on a firing range where three out of four M2 BMGs had cook-offs following prolonged firing. Some problems noted during the initial evaluation of this weapon by the US Marines in 2001 included: 1) Significantly increased reload times compared to the M2 BMG. 2) Lengths of rounds were repeatedly pulled from the 100 round magazines by the airstream, resulting in hazards to personnel and equipment. 3) Lack of a flash suppressor, which made this weapon almost impossible to use with night-vision equipment. The feed system for 600 round magazines has been modified to reduce the air stream problem and FN Herstal has added a flash suppressor, as can be seen below in the second photograph. (from http://www.navweaps.com/Weapons/WNUS_50cal-M3M_MG.htm)
 GAU-15/A machine gunThe GAU-15/A utilized on the H-46, UH-1N and H-53 series aircraft is a crew served, recoil operated, belt fed, air cooled, percussion fired weapon, with a rate of fire of 750 rounds per minute. The gun system consists of the GAU-15/A (XM-218) cal. 50 machine gun, a pintle mount assembly, brass collection bag, and ammunition can bracket assembly. The pintle mount assembly is attached at personnel or cargo doors or windows of the aircraft. The ammunition can bracket holds a single 100 round can of linked cal. 50 percussion primed ammunition. Additional cans of ammunition are carried inside the aircraft to allow for rapid reloading. (from http://www.fas.org/man/dod-101/sys/ac/equip/gau-15.htm)


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