| M242 Bushmaster | |
|---|---|
 U.S. Army press photo of a M242 Bushmaster | |
| Type | Chain gunautocannon |
| Place of origin | United States |
| Service history | |
| In service | 1981–present |
| Used by | SeeOperators |
| Production history | |
| Designer | Hughes Helicopters[1][2] |
| Designed | 1976 |
| Manufacturer | Hughes Helicopters (1981–1985)[1][3] McDonnell Douglas Helicopters (1985–2002)[3] Alliant Techsystems (2002–2015)[3] Orbital ATK (2015–2018)[3] Northrop Grumman Innovation Systems (2018–present)[3] |
| Produced | 1981–present |
| No. built | >11,000[4] |
| Variants | Seevariants |
| Specifications | |
| Mass | 119kilograms (262 lb)[4] |
| Length | 2,672 mm (105.2 in)[4] |
| Barrel length | 2,175 mm (85.6 in) |
| Width | 318 mm (12.5 in)[4] |
| Height | 373 mm (14.7 in)[4] |
| Shell | 25 × 137 mm |
| Barrels | Single barrel (progressive RH parabolic twist) |
| Action | Externally powered, chain driven,open bolt |
| Rate of fire | Cyclic: 200 rpm with 1 hp or 500 rpm with 8 hp |
| Muzzle velocity | 1,100metres per second (3,600 ft/s) |
| Effective firing range | 3,000metres (9,800 ft) |
| Maximum firing range | 6,800 metres (22,300 ft) |
TheM242 Bushmasterchain gun is a25 mm (25×137mm) single-barrel chain-drivenautocannon. It is used extensively by theU.S. military, such as in theBradley fighting vehicle, as well as by otherNATO members and some other nations in groundcombat vehicles and various watercraft.Hughes Helicopters in Culver City, California, was the original designer and manufacturer.[1][2] As of 2019[update],Northrop Grumman Innovation Systems produces the gun.[4]
It is an externally-powered, chain-driven, single-barrel weapon that may be fired in semi-automatic, burst, or automatic modes. It is fed by a metallic link belt and has dual-feed capability. The termchain gun derives from the use of aroller chain that drives the bolt back and forth. The gun can destroy lightly armored vehicles and aerial targets (such as helicopters and other slow-flying aircraft). It can also applysuppression fire against exposed troops, dug-in positions, and occupied built-up areas. The standard rate of fire is 200rounds per minute. The weapon has an effective range of 2,000metres (6,600 ft),[5] depending on the type of ammunition used. With over 11,000 units sold worldwide, it is one of the most successful modern autocannons.[4]
_while_monitoring_a_small_boat_transiting_from_the_merchant_vessel_MV_F.jpg)
Unlike most automaticfirearms, the M242 does not depend on gas orrecoil to actuate its firing system. Instead, it uses a 1 hp (0.75 kW)DCmotor, positioned in thereceiver to drive the chain anddual-feed system. This system uses sprockets and extractor grooves to feed, load, fire, extract, and eject rounds. A system of clutches provides for an alternate sprocket to engage and thus allows the gunner to switch betweenarmor-piercing andhigh-explosive rounds.
The weapon assembly consists of three parts: thebarrel assembly, the feeder assembly, and the receiver assembly. The three-part structure makes it possible for a two-person team to install or remove the system (under ideal conditions) despite its considerable total weight.
The M242 weapon system has both electrical and manual fire control and can be operated electrically or manually. The gunner can choose from three rates of fire:
![[icon]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aWiki_letter_w_cropped.svg) | This sectionneeds expansion. You can help byadding to it.(March 2020) |
The Bushmaster project started as an offshoot of theUS Army'sMICV-65 program that was attempting to introduce a newinfantry fighting vehicle to replace their existingM113 armored personnel carriers. Part of this program called for a new scout vehicle to replace theM114, a parallel development taking place under theXM800 Armored Reconnaissance Scout Vehicle. Both the XM800 and the cavalry version of the XM701 MICV vehicles were armed with theM139, a US-built version of theHispano-Suiza HS.820 20 mm autocannon. During the testing phase, the Army eventually rejected the XM701 and started work on a newer design known as the XM723. Soon after the XM800 was also rejected. This led to the combination of the two programs, moving the scout role to the cavalry version of the XM723.
At the same time, the M139 proved to be disappointing and a contract for a new weapon to replace it started as a competitive development in 1972 simultaneously atFord'sAeronutronic Division with thePFB-25 (self-powered weapon) and theHughes Helicopters' Ordnance Division (externally-powered,)[2] under theSumma Corporation as theVehicle Rapid-Fire Weapons System-Successor, orVRFWS-S. This was essentially a power-driven gun firing similar 20 mm ammunition to the HS.820, the power-driven mechanism was to ensure operation even in the case of a misfire.
Progress on the VRFWS-S was slow, and eventually resulted in a switch to a much more powerful, 25 mm, round. Similar delays in the MICV program meant the ultimate vehicles descending from their efforts, the M2/M3 Bradley fighting vehicle, did not enter production until 1981, by which point the Bushmaster had matured. Since 1990, there have been several enhancements made upon the weapon, resulting in theenhanced 25 mm gun.
To date, more than 10,500 weapons are in service. One of the major reasons for this popularity is the extremely reliable nature of the weapon. It has a rating of 22,000 mean rounds between failure (MRBF), much higher than many comparable devices.
A wide range of ammunition has been developed for this weapon, providing it with the capability to defeat the majority ofarmored vehicles it is likely to encounter, up to and including somelight tanks. The ammunition used in the M242 may also be used in a variety of weapons such as theGAU-12 Equalizer, the FrenchGiat M811, or the SwissOerlikon KBA weapon system. It has the capability to fire U.S. manufactured ammunition as well as theNATO equivalents thereof. Primarily though, it fires six types of rounds: the M791, M792, M793, M910, MK210, and M919.
The M242 is currently in use by theUnited States Army, theUnited States Navy, theUnited States Marine Corps, theUnited States Coast Guard, theNew Zealand Army, theRoyal New Zealand Navy, theNorwegian Army, theSpanish Army, theSri Lanka Navy, theSwiss Army, theCanadian Army, theRoyal Canadian Navy, theAustralian Army, theRoyal Australian Navy, theIsraeli Navy, thePhilippine Navy, thePhilippine Army, theSingapore Army, and theRepublic of Singapore Navy as well as several others, including since 2023 theArmed Forces of Ukraine.[7] The wide usage has resulted in several variations and modifications on the standard M242 weapon system.
_1st_Light_Armor_Reconnaissance_Battalion_Landing_Team_(1st_LAR_BLT_1-1)_perform_maintenance_on_Light_Armored_Vehicles.jpg)
![An Mk38. The M242 has a characteristic fluted gun barrel to reduce weight and assist cooling.[8]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aMk_38_25mm_Machine_Gun_System.jpg)
_ejects_casings_d.jpg)
The M242 is standard equipment on the U. S. Army M2 and M3 Bradley fighting vehicles; it is also in use on theLAV-25. Before the project was cancelled, theMk44 Bushmaster II 30 mm chain gun (a successor to the M242) was used on the Marine Corps'Expeditionary Fighting Vehicle (EFV).
The M242 is also a popular choice of primary armament forarmored fighting vehicles manufactured around the world, such as Singapore'sBionix AFVs and as theRafael Overhead Weapon Station-25 mounted on upgradedM113A2 Ultra IFVs.[9]
Work on an upgraded weapon began in 1990. In the upgrade program, all three major systems and seven minor systems were improved. The modifications began with introducing achrome-lined barrel, an enhanced feeder, and an enhanced receiver. The weapon systems also received minor upgrades such as quick-detachable link covers, a larger breech assembly, a high efficiencymuzzle brake, longerrecoil, an integral round counter, an extended lifefiring pin and spring, and a triple-spring drive clutch. Upgraded weapons were first put to use on the M2A3 Bradley, the fourth version of the M2 Bradley fighting vehicle.
In 1977, theU. S. Navy realized that it needed a replacement for theOerlikon 20 mm Mk 16 series of guns. In 1986, this requirement was satisfied with the introduction of theMk 38 Mod 0 weapons system. A derivative of the M242 system, the Mk 38 consists of the M242 chain gun and theMk 88 Mod 0 machine gun mount. It provides ships with defensive and offensive gunfire capability for the engagement of a variety of surface targets. Designed primarily as a close-range defensive measure, it provides protection againstpatrol boats,floating mines, and various shore-based targets.
Recently, several US Navy platforms have been outfitted with a newer version, theTyphoon Weapon System designatedMk 38 Mod 2,[10][11] which is remotely operated and includes an electronic optical sight, laser range-finder, FLIR, and a more reliable feeding system, enhancing the weapon system's capabilities and accuracy. In 2006 theSri Lanka Navy added the M242 to its fleet offast attack craft.[12]
The system is also in use by theRepublic of Singapore Navy'sFormidable-classfrigates andEndurance-classlanding platform dock ships[13] and were deployed as part of coalition forces' port security efforts in Iraq as well as anti-piracy roles in theGulf of Aden.[14] Aside from that, theSingapore Police Coast Guard's new coastal patrol craft (NCPC) has adopted the system as its main armament.[15]
The Mod 3 updates electronics and adds a coaxial 7.62 mm machine gun with a 570-round-per-minute rate of fire.[16][17][18]
The Turkish-madeAselsan STOP stabilizedweapon station can be fitted with an M242 Bushmaster.[19]
BAE and Boeing teamed together after a March 2011 contract to add adirected energy weapon to the Mk 38 Mod 2 gun mount, known as theMk 38 Mod 2 tactical laser system. The TLS combines a Boeing-designed solid-state laser with the existing BAE-manufactured Mk 38 mount to deliver high-precision accuracy against fast surface and air threats including speed boats andunmanned aerial vehicles (UAVs). Laser power levels can be adjusted depending on the target and mission objectives.[20][21] Originally, the system was armed with a 10 kW laser, but in April 2017 BAE announced they had increased power to 60 kW.[22]
In April 2012, BAE unveiled a potential version of the system mount, developed in collaboration withRafael Advanced Defense Systems. It is visually distinctive from previous versions with its stealthy housing, which also protects the gun from weather and allows for easier access to internal components through large access panels. The upgrade mounts a largerAlliant TechsystemsMk44 Bushmaster II 30 mm cannon for a 500-meter range increase, as well as a coaxial .50 caliberM2 heavy machine gun. Elevation is increased to +75 degrees for engaging UAVs and helicopters, and ammunition storage is greater at 420 30 mm rounds. Other features include a larger manual fire control panel, an offset mode specifically for firing warning shots, and a surveillance mode where the gun can be pointed away from a target but the EO sensor remains pointed in the target direction. Although it has a high degree of commonality and has the same footprint as previous models, the upgrade is 20 percent heavier due to the greater ammo load.[23]
Australia[24]
Canada
Croatia
Georgia
Israel
Malaysia
New Zealand
Norway
Philippines
Singapore[9][13][15]
Spain
Sri Lanka[12]
Switzerland
Turkey
Ukraine
United States[Last updated on 12 June 2010]
