The Mk44 Bushmaster II is a 30 mm chain gun manufactured by Alliant Techsystems.
It is a derivative of the 25 mm M242 Bushmaster, and uses 70% of the same
parts as the M242 while increasing the firepower by as much as 50% with the 20%
increase in caliber size. The barrel is chromium-plated for extended life. The
gun uses standard GAU-8 Avenger ammunition that is available in API, HEI
and APFSDS-T variants. The gun can be converted to a caliber of 40 mm, which
involves changing the barrel and a few key parts, to use the Super 40
cartridge. It can also be converted to use the 30x170 mm RARDEN cartridge.
History The Bushmaster II is the standard
primary armament of Bionix-II AFV currently in service with the Singapore
Army, the KTO Rosomak in Polish service as well as that of the CV90 AFVs in
Finnish, Norwegian and Swiss service. Although the United States Air Force
selected this cannon to replace the 25 mm and 40 mm guns on its fleet of
AC-130U gunships in 2007, this plan was later canceled. The United States Marine
Corps' Expeditionary Fighting Vehicle, which has been canceled, was expected to
be armed with this cannon as well. Some United States Navy vessels, such as the
new San Antonio-class amphibious transport dock are armed with the
Bushmaster II for surface threat defense.
The Bushmaster II cannon is used in the DS30M Mark 2 Automated Small Calibre Gun
point defense system that is fitted to the Royal Navy's Type 23 frigates.
The USAF had experimented with installing Bushmaster II cannons on
their AC-130U gunships in place of the GAU-12 and Bofors 40 mm cannons. On 11
August 2008, the effort was canceled because of problems with the
Bushmaster's accuracy in tests "at the altitude we were employing it." There
were also schedule considerations that drove the decision. On 9 July 2012, the
Air Force type classified a new version of the Bushmaster called the GAU-23/A.
The cannon will be used on the AC-130W and the AC-130J gunships.
The U.S. Navy uses the Mk44 Bushmaster II in the Mk 46 Mod 2 Gun Weapon System.
The GWS is produced by General Dynamics to give warships protection against
small, high-speed surface craft. A Mk 46 turret consists of the 30 mm chain gun,
a forward looking infrared sensor, a low light television camera, and a laser
rangefinder. The guns fire at 200 rounds per minute and are fed by a 400-round
magazine through 200-round dual feeds. Effective range is 2,200 yds for
full-caliber high-explosive or armor-piercing ammunition, which can be
extended when using sub-caliber rounds. The Mk 46 GWS is permanently installed
on the San Antonio-class amphibious transport dock and can be installed on
Freedom-class and Independence-class Littoral Combat Ships as part of the
surface warfare package. In 2012, the Navy decided to replace the Mk 110 57 mm
cannons on Zumwalt-class destroyers with the Mk 46 GWS.
In early 2015, the U.S. Army approved an upgrade for 81 Stryker vehicles of a
Stryker Brigade Combat Team deployed in Europe to be upgunned with the Mk44 30
mm Bushmaster cannon to increase their lethality against other light armored
vehicles used by Russia in the theater. The cannons will be installed by 2018,
and may be the first step in adding the Bushmaster to the entire active fleet of
about 1,000 Strykers. XM813
The XM813 Bushmaster is based on the Mk44 and is offered as an upgrade for
M1126 Stryker and M2 Bradley vehicles, as well contended to be the primary
armament of the GCV Infantry Fighting Vehicle. Improvements include a one-inch
longer barrel, integral mount to increase first round hit probability by
up to 10 percent, and dual recoil system to enhance accuracy and cope with future
hotter propellants. It can have a next-round select, linkless feed system.
The 30 mm chain gun can fire Mk310 Programmable Air Burst Munition rounds
to attack targets in defilade. The United States Army Research, Development
and Engineering Command helped enhance the XM813 mainly for safety and turret
integration. By changing five parts, the gun caliber can be increased to 40 mm.
As of November 2013, the XM813 was being tested at Aberdeen Proving Ground over
three months to ensure reliability levels of 40,000 mean rounds between
failures. Long-term plans are to equip vehicles with the Bushmaster III
35mm/50mm cannon. The XM813 was demonstrated on 10
September 2014 at the ARDEC Digital Multi-Purpose Range Complex. The gun was
mounted on a Bradley Fighting Vehicle and fired at targets up to 1,500 meters
away. An enhanced fire control system improves long-range accuracy to kill
targets with fewer bursts, sometimes as few as two or three rounds instead of
10. The XM813 30 mm cannon is intended to replace the M242 Bushmaster 25 mm
chain gun, and could potentially be mounted on vehicles other than the
Bradley. Two capabilities not demonstrated were its linkless
ammunition with airburst capabilities; airburst rounds increase lethality by
enabling engagement of targets in defilade when they would otherwise only
be suppressed by fire. Users
Brazil Army: VBTP-MR Guarani
Navy: Port of Spain class corvette Czech Republic
Army: Pandur II CZ Finland
Army: CV9030FIN Japan
Coast Guard: Hateruma-class patrol vessel
Netherlands Navy: Holland-class offshore patrol
vessel and Karel Doorman-class support ship
Norway Army: CV9030N
Poland Army: KTO Rosomak
Portugal Army: Pandur II
Singapore Army: Bionix II
Switzerland Army: CV9030CH
United Kingdom Navy: Type 23 frigate
United States Navy: San Antonio–class transport ship,
Littoral combat ship and Zumwalt-class destroyer
Air Force: AC-130J Republic of Ireland
Army: Mowag Piranha See also
Bushmaster 25 mm chain gun Bushmaster III 35/50 mm chain gun
Bushmaster IV 40 mm chain gun 30mm Shipunov 2A42—Soviet/Russian
autocannon 30mm L21A1 RARDEN—British autocannon
Future Combat Systems Infantry Carrier Vehicle
References :www.atk.comdocuments/108279_01_Mk44.pdf
Notes External links
Alliant Techsystems Mk44 Bushmaster Automatic Cannon Fact Sheet
Alliant Techsystems GAU-23 Bushmaster Automatic Cannon Fact Sheet
30mm Bushmaster II on NavWeap.Com Mk44 Bushmaster II 30mm on
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