Overview:
The M249 light machine gun (LMG), previously designated the M249 Squad Automatic Weapon (SAW), and formally written as Light Machine Gun, 5.56 mm, M249, is an American version of the FN Minimi, a light machine gun manufactured by the Belgian company FN Herstal (FN). The M249 is manufactured in the United States and is used by all branches of the U.S. Armed Forces. The gun was introduced in 1984 after being judged the most effective of a number of candidate weapons to address the lack of automatic firepower in small units. The gun provides the heavy volume of fire of a machine gun with accuracy and portability approaching that of a rifle to infantry squads. The M249 is gas-operated and air-cooled. It has a quick-change barrel, allowing the gunner to rapidly replace an overheated or jammed barrel. A folding bipod is attached near the front of the gun, though a M192 Lightweight Ground Mount tripod is also available. It can be fed from both linked ammunition and STANAG magazines, like those used in the M16 and M4. This allows the SAW gunner to use rifleman's magazines as an emergency source of ammunition in the event that he runs out of linked rounds. However, this will often cause malfunctions because the magazine spring has difficulty feeding rounds quickly enough to match the SAW's high cyclic rate. M249s have seen action in every major conflict involving the United States since the 1991 Gulf War. Soldiers are generally satisfied with the weapon's performance, though there have been many reports of clogging with dirt and sand. Due to the weight and age of the weapon, the U.S. Marine Corps (USMC) is considering designs for an infantry automatic rifle, which is planned to complement and partially replace the M249 in their service. The M249 is a belt-fed light machine gun. It fires the 5.56x45 mm NATO cartridge, usually a combination of one M856 tracer and four M855 ball cartridges fed from M27 linked belts. Belts are typically held in a hard plastic or soft canvas box attached to the underside of the weapon. It fires from an open bolt and is gas operated. When the trigger is pulled, the bolt and bolt carrier move forward under the power of the recoil spring. A cartridge is stripped from the belt, chambered, and discharged, sending a bullet down the bore. Expanding propellant gases are diverted through a hole in the barrel into a chamber. This pressure moves a piston providing the energy to extract and eject the spent casing as well as advance the belt and compress the recoil spring, thus preparing for subsequent shots. At 1,041 mm (41 in) long and 7.5 kg (17 lb) in weight (10 kg (22 lb) including a 200-round belt and plastic ammo box), the M249 is a cumbersome weapon. The barrel has a rifling twist rate of one turn in 180 mm (7 in). Because firing heats up the bore, the air-cooled barrel is equipped with a mechanism to remove and replace the barrel assembly with a spare.[26] A folding bipod with adjustable legs is attached near the front of the weapon, though there are provisions for hard-mounting to a M192 Lightweight Ground Mount tripod or vehicle mount. The M249 provides accuracy approaching that of a rifle, combined with the sustained volume of fire of a machine gun. Its original gas regulator offered two different gas port sizes, allowing cyclic rates of fire of 750 rounds per minute (r/min) or 1,000 r/min. The latter setting was intended for adverse conditions such as an excessively dirty firearm or cold weather. The two-position gas regulator was discarded as part of a product improvement program. Sustained rate of fire, the rate of fire at which the gunner can fire continuously without overheating, is approximately 85 r/min.
Specifications:
Type
- Squad automatic weapon/Light machine gun.
- Belgium.
- 7.5 kg (17 lb) empty.
- 10 kg (22 lb) loaded.
- 1,041 mm (41 in).
- 521 mm (21 in).
- 5.56x45mm NATO.
- Gas-operated.
- Open bolt.
- 750–1,000 rounds/minute.
- 915 m/s (3,002 ft/s).
- 1,000 m (1,094 yd).
- M27 linked belt.
- STANAG magazine.
No comments:
Post a Comment