M252 mortar | |
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Type | Mortar |
Place of origin | United Kingdom |
Service history | |
Used by | Estonia |
Wars | Gulf War |
Specifications | |
Weight | 41.3 kilograms (91 lb) |
Barrel length | 1.27 metres (4 ft 2 in) |
Crew | 5 |
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Caliber | 81 millimetres (3.2 in) |
Rate of fire | 8–16 rpm sustained 20–30 rpm in exceptional circumstances and for short periods |
Effective range | HE: 93–5,935 m (104–6,490 yd) |
Feed system | manual |
The M252 81 mm medium weight mortar is an American smooth bore, muzzle-loading, high-angle-of-fire weapon used for long-range indirect fire support to light infantry, air assault, and airborne units across the entire front of a battalion zone of influence. In the U.S. Army and U.S. Marine Corps, it is normally deployed in the mortar platoon of an infantry battalion.
Contents |
The M252 system weighs 91 lb (41 kg) completely assembled and is composed of the M253 Cannon (35 lb, 16 kg), M177 Mount (27 lb, 12 kg), M3A1 Baseplate (29 lb, 13 kg), and the M64A1 Sight Unit (2.5 lb, 1.1 kg). The mount consists of a bipod and a base plate which is provided with screw type elevating and traversing mechanisms to elevate/traverse the mortar. The M64A1 sight unit (also used on the M224) is attached to the bipod mount. The M252 is a gravity-fired smooth bore system. Attached to the muzzle of the weapon is the Blast Attenuation Device (BAD), used to reduce the blast effects on the mortar crew. To increase cooling efficiency, the breech end is finned, though first-hand accounts attest that the level of cooling is negligible. The cannon also has a crew-removable breech plug and firing pin.
The M252 is an adaptation of the British 81mm L16A2 mortar developed in the 1950s. It entered service with the U.S. Army and replaced the previous 81 mm M29 mortar in 1986. It was adopted due to the extended range (from 4,500 meters to 5,650 meters) and enhanced lethality. In the U.S. it is produced by Watervliet Arsenal.
A much lighter version, the M252A1 was fielded for the first time in 2011. By reducing the number of parts and using lightweight materials, the total weight was reduced by 20.8 pounds. In the next several years, all U.S. Army M252s will be replaced by the M252A1.[1] As part of the same program, a lightweight version of the M224 mortar was developed.
The M252 uses a crew of five enlisted personnel to operate: the squad leader, the gunner, the assistant gunner, the first ammunition bearer, and the second ammunition bearer.
While the M252 does fire a weapon specific series of ammunition, it can also fire rounds from the M29 Mortar (only at charge 3 or below though). The M252 Mortar can fire the following principal classifications of training and service ammunition.
The M224 rounds have two fuze types: the Multioption Fuze (M734) and the Point-Detonating Fuze (M935). The M734 is used for the M720 HE round and can be set to function as proximity burst, near-surface burst, impact burst, or delay burst.
The range of mortars are controlled by what are referred to as "charges." Charges are semi-circular nitrocellulose donuts that resemble a puffy letter "C." Ammunition for the M252 mortar come with four charges. Longer range shots require more propellant than can be easily stored in the tail of the round, hence the necessity of the charges to be placed on the round. Once a target is ranged, the correct charge is placed on the round by removing the charges from the projectile. Once the charges are verified by the section leader, the round is dropped down the muzzle of the tube. The round, pulled by gravity, accelerates down the smooth bore of the mortar until the primer (in the base of the tail boom of the round) strikes the firing pin located in the bottom of the mortar tube. The primer detonates igniting the charge in the tail fin which in turn ignites any of the C-charges on the round. The expanding gas created by the burning charges push against the obturator band on the round, sealing the gasses and gives the round forward momentum. The round is accelerated by the gasses until it leaves the end of the tube.
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