page_title: Alliant Techsystems
section_title: Bushmaster autocannons
hierarchical_section_title: Alliant Techsystems / Groups / ATK Defense / Bushmaster autocannons
caption_attribution_description: English: October 2016 image of Oshkosh L-ATV fitted with Orbital ATK's M230 LF 30mm lightweight automatic chain gun mounted on EOS R400S-MK2 remote weapon station
context_page_description: Alliant Techsystems Inc. was an American aerospace, defense, and sporting goods company with its headquarters in Arlington County, Virginia, in the United States. The company operated in 22 states, Puerto Rico, and other countries. ATK's revenue in the 2014 fiscal year was about US$4.78 billion.
  On April 29, 2014, ATK announced that it would spin off its Sporting Group and merge its Aerospace and Defense Groups with Orbital Sciences Corporation.
  The spinoff of the Sporting Group to create Vista Outdoor and the merger leading to the creation of Orbital ATK were completed on February 9, 2015; both companies began operations as separate entities on February 20, 2015.
context_section_description: The M242 Bushmaster is a 25 mm (25×137mm) chain-fed autocannon. It is used extensively by the United States and NATO forces in ground combat vehicles and watercraft. Originally, the weapon was designed and manufactured by McDonnell Douglas. It is an externally powered, chain driven, single-barrel weapon which may be fired in semi-automatic, burst, or automatic modes. It is fed by a metallic link belt and has dual-feed capability. The term "chain gun" derives from the use of a roller chain that drives the bolt back and forth. The gun can destroy lightly armored vehicles and aerial targets, such as helicopters and slow-flying aircraft. It can also suppress enemy positions such as exposed troops, dug-in positions, and occupied built-up areas. The standard rate of fire is 200 rounds per minute. The weapon has an effective range of 3,000 metres (9,800 ft), depending on the type of ammunition used.
  The Mk44 Bushmaster II is a 30 mm chain gun also manufactured by ATK.  It is a derivative of the 25 mm M242 referenced above and uses 70% of the same parts as the M242. The Mk 44 Bushmaster II is the standard primary armament of the 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. 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 XM813 Bushmaster, also produced by ATK Defense, is based on the Mk44 and is offered as an upgrade for M1126 Stryker and M2 Bradley.  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.
caption: 2016: Oshkosh L-ATV (configured as JLTV) with EOS R-400S-MK2 remote weapon system armed with Orbital ATK's M230-LF 30mm lightweight automatic chain gun.
exif: {"Image ImageWidth": "3000", "Image ImageLength": "2400", "Image BitsPerSample": "[8, 8, 8, 8]", "Image Compression": "LZW", "Image PhotometricInterpretation": "5", "Image Make": "NIKON CORPORATION", "Image Model": "NIKON D800", "Image Orientation": "Horizontal (normal)", "Image SamplesPerPixel": "4", "Image XResolution": "300", "Image YResolution": "300", "Image PlanarConfiguration": "1", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CC 2015 (Macintosh)", "Image DateTime": "2016:09:12 10:07:59", "Image ExifOffset": "316", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1126", "Thumbnail JPEGInterchangeFormatLength": "6844", "EXIF ExposureTime": "1/160", "EXIF FNumber": "11", "EXIF ExposureProgram": "Aperture Priority", "EXIF ISOSpeedRatings": "200", "EXIF SensitivityType": "Recommended Exposure Index", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2016:08:31 15:56:04", "EXIF DateTimeDigitized": "2016:08:31 15:56:04", "EXIF ShutterSpeedValue": "915241/125000", "EXIF ApertureValue": "6918863/1000000", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "4", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "24", "EXIF SubSecTimeOriginal": "6", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "3000", "EXIF ExifImageLength": "2400", "EXIF FocalPlaneXResolution": "16780511/8192", "EXIF FocalPlaneYResolution": "16780511/8192", "EXIF FocalPlaneResolutionUnit": "3", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CVAPattern": "[2, 0, 2, 0, 0, 1, 1, 2]", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Manual", "EXIF DigitalZoomRatio": "1", "EXIF FocalLengthIn35mmFilm": "24", "EXIF SceneCaptureType": "Standard", "EXIF GainControl": "None", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF SubjectDistanceRange": "0", "EXIF BodySerialNumber": "3004036", "EXIF LensSpecification": "[18, 35, 7/2, 9/2]", "EXIF LensModel": "18.0-35.0 mm f/3.5-4.5"}