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40-480: AT-4 may refer to: AT4 , a Swedish unguided, portable, single-shot anti-tank weapon AT-4 Spigot , a Soviet guided anti-tank missile Curtiss AT-4 Hawk , U.S. Army biplane advanced trainer of 1927 [REDACTED] Topics referred to by the same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change

80-610: A line-of-sight penetration of 600 mm. However, the project was cancelled due to the dissolution of the Soviet Union and the subsequent cuts in Western defence budgets. Beyond-armour effect The phrase now has become more or less standard in modern military terminology. During World War II , man-portable antitank weapons using shaped charge warheads , more commonly known today as HEAT projectiles, came into widespread use with almost all armies. These warheads have

120-1132: A projectile heavier than the HEDP AT4 is needed. This combines a shallow-coned HEAT warhead (resulting in low penetration but producing a wide hole) with a tandem-charge and a follow-through high-blast warhead. It has two settings: either to destroy bunkers or to mouse-hole a building wall for combat entry. Extended range (ER) – Anti-armor version with HEAT warhead. Range is extended from 300 to 600 metres (980 to 1,970 ft), with increased penetration up to 46 centimetres (18 in) of RHA. These major improvements add only about 2 kilograms of mass, despite being CS models. High explosive (HE) – High explosive anti-personnel weapon that can be set for impact or air-burst detonation, with an effective range up to 1,000 metres (3,300 ft). M136 AT4 – American version with modified launch tube bumpers, sights, and slings. XM919 Individual Assault Weapon (also known as AT4CS TW) – American future variant, to enter service in 2025, and be delivered by 2029 for USD $ 500 million. Bunker-busting (AT8) – An AT4 version where

160-634: Is a development of the 74-mm Pansarskott m/68 (Miniman) adopted by the Swedish Army in the late 1960s. Like the m/68, the AT4 was designed by Förenade Fabriksverken (FFV) and manufactured at their facility at Zakrisdal, Karlstad , Sweden. FFV began research on a replacement for the m/68 in 1976, deliberately designing an individual anti-armour weapon that would not be able to defeat the heavy armour protection of MBTs (main battle tanks) in frontal engagements, believing that to be counterproductive. The AT4

200-495: Is a word play on the 84 mm caliber of the weapon, (84) 'eighty four' being a homophone of 'A-T-4'. The name also doubles as an alpha-phonetic word play on the weapon's role, due to "AT" being a common military abbreviation for "anti-tank". The name was created for export purposes as the nickname "eighty-four" was already a common English nickname for the Carl Gustaf 8.4 cm recoilless rifle after its caliber. The AT4

240-467: Is balanced by the inertia of propellant gases ejecting from the rear of the barrel. But unlike the Carl Gustaf, which uses a heavier and more expensive steel tube with rifling , the disposable AT4 design greatly reduces manufacturing costs by using a reinforced smoothbore fiberglass outer tube. Being a disposable gun also allows for lighter and cheaper construction. In a single-use disposable gun,

280-404: Is enclosed in the AT4 outer tube. When the gases build up to the correct pressure level, the blowout plug disintegrates, allowing the proper amount of gases to be vented to the rear, balancing the propellant gases pushing the projectile forward. The AT4 adopted a unique method developed earlier by FFV: the spring-loaded firing rod is located down the side of the outer tube, with the firing pin at

320-437: Is intended to give infantry units a means to destroy or disable armoured fighting vehicles and fortifications , although it is generally ineffective against more modern main battle tanks (MBTs), especially those with reactive armour , unless weaker sections of armour are exploited. The launcher and projectile are manufactured prepacked and issued as one unit of ammunition, with the launcher discarded after one use. The AT4

360-498: Is not a rocket launcher strictly speaking, because the explosive warhead is not propelled by a rocket motor . Rather, it is a smooth-bore recoilless gun (as opposed to a recoilless rifle , which has a rifled barrel). Saab has had considerable sales success with the AT4, making it one of the most common light anti-tank weapons in the world. The M136 AT4 is a variant used by the United States Army . The name AT4

400-431: Is present in the back blast area. If firing from the prone position , they must also place their legs well to the side to avoid burning himself. Then, the gunner moves back the front and rear sight covers, allowing the sights to pop up into their firing positions. The AT4 has iron sights that were originally developed for the cancelled Viper , and are similar in concept and use to those on assault rifles. They then remove

440-652: The Vietnam War . The North Vietnamese and their allied forces in South Vietnam were equipped with two types of light anti-armour weapons. One was the 1950s era B-40 , which was a Chinese manufactured version of the Russian RPG-2, and the other was the newer RPG-7 . The RPG-2 had a shallow cone and the RPG-7 a deep cone. The B-40 had a maximum penetration against armour of approximately 150 mm while

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480-676: The AT4 as the Pansarskott m/86 ( Pskott m/86 ), with the addition of a forward folding hand grip to help steady the AT4 when being aimed and fired. The forward folding grip is the only difference between the AT4 adopted by Sweden and the US Army version. Due to the urban combat conditions that US military forces faced regularly during the Iraq War , the US Army Close Combat Systems manager in charge of purchases of

520-663: The AT4 firing and is favoured by the Swedish army because of the added realism of the back blast as compared to the "plonk" sound of the 9mm round (similar to the sound of a finger tapping on an empty can). There are several different projectiles for the AT4. Because it is a one-shot weapon, projectiles are preloaded into the launcher tubes. High-explosive anti-tank (HEAT) – Can penetrate up to 45 centimetres (18 in) of rolled homogeneous armour (RHA) with beyond-armour effect . High-explosive dual purpose (HEDP) 502 – For use against bunkers , buildings, enemy personnel in

560-513: The AT4 outer tube is built to take the stress of just one firing; it is not reusable and cannot be reloaded. The AT4 can mount an optical night sight on a removable fixture. In US military use, the launcher can be fitted with the AN/PAQ-4C, AN/PEQ-2, or the AN/PAS-13 night sights. The AT4 requires little training and is quite simple to use, making it suitable for general issue. However, as

600-467: The AT4 suspended orders for the standard version of the AT4; US military forces instead only ordered the AT4 CS (Confined Space) version. The AT4 may be considered a disposable, low-cost alternative to a Carl Gustaf 8.4 cm recoilless rifle . The AT4 took many of its design features from the Carl Gustaf, which operates on the principle of a recoilless weapon , where the forward inertia of the projectile

640-644: The B-40 proved more effective than the RPG-7 against non-armoured targets, like the bunkers at fire base camps. There are many stories from U.S. Vietnam veterans of the enemy attacking or ambushing very effectively with the B-40. The U.S. Army also discovered that in combat, with rare exceptions, more than one hit by the M72 LAW rocket was required to disable or kill the North Vietnamese PT-76 light tank. The combat record of light anti-armour weapons

680-993: The British LAW 80 , the German Armbrust , the French APILAS , the Norwegian M72E4 (an upgraded M72 LAW), the US Viper (for baseline comparison purposes) and the Swedish AT4. The US Army reported to Congress in November 1983 that the FFV AT4 came the closest to meeting all the major requirements established to replace the M72 LAW, with the Armbrust coming in second. Though very impressed with

720-464: The HEAT warhead's particle stream. There has been speculation that the liner in the AT4's HEAT warhead is constructed of a special aluminum alloy. Others have stated it is primarily a copper liner with a secondary liner of aluminum bonded to the back of the copper liner. Another clue to the effectiveness of the AT4 is the presence of a "focus ring" to concentrate the blast. All public statements to 1984 on

760-517: The RPG-7 penetration was more than double that of the B-40. But to the surprise of the North Vietnamese, the B-40, while not effective against heavy tanks, was far more effective than the RPG-7 in killing or wounding the occupants of light armoured vehicles, and in igniting the ammunition storage or the vehicle's fuel, including the more modern M113 APC which U.S. and South Vietnamese forces at that time operated in large numbers. In addition,

800-580: The Swedish Army began the first evaluation firings of the prototype AT4s in the spring of 1981, with 100 tested by early 1982. Even before the AT4 had been adopted by Sweden, it was entered into a United States Army competition for a new anti-tank weapon mandated by Congress in 1982 when the FGR-17 Viper failed as a replacement for the M72 LAW . Six weapons were tested in 1983 by the US Army:

840-474: The advantage of not being affected by the projectile's velocity. They penetrate armour by the detonation of an explosive charge fitted in a liner in the shape of a cone or, more precisely, an ogive . The liner is often made of a soft metal, such as copper. Detonation of this shaped charge turns it into a highly focused stream moving forward at extreme speeds. Like medium and high velocity solid shot armour piercing projectiles, these warheads also cause spalling on

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880-411: The almost complete lack of recoil, means that relatively large projectiles (comparable to those found in mortars and artillery systems) can be utilised, which would otherwise be impossible in a man-portable weapon. In the system originally developed by FFV for the Carl Gustaf, a plastic blowout plug is placed at the centre rear of the shell casing containing the projectile and propellant, which itself

920-452: The barrel only needs to be able to contain a single pressure spike when firing, when it can be disposed of, even if it is ruined, burnt-out and strained, unlike traditional guns which are required to survive many pressure spikes without failure and thus need to be strongly overbuilt and made of heat-proof materials. Pressures are also kept quite low compared to many traditional guns. This lightweight and thin barrel and low pressure, combined with

960-410: The cost of each launcher makes regular live-fire training very expensive, practice versions exist that are identical in operation but fire reloadable 9×19mm or 20mm tracer ammunition . Both practice cartridges are unique to their respective weapons, with their trajectory matched to that of the live round. The 20mm version also has a recoilless weapon effect with the same high noise and back blast as

1000-467: The design of the AT4's warhead, being willing only to describe its effects. Defense journalists and military experts have speculated on the warhead's design. A cutaway photo of the AT4's projectile gave clues. Instead of the standard cone shape liner used by other HEAT warheads, the AT4 has a unique trumpet-shaped liner. Trumpet-shaped liners are believed to be more effective in resisting the counter-blast of reactive armour tiles, that explode and disrupt

1040-429: The diameter of a pencil lead on the turret's inner face. If, on the other hand, the ogive is shallow, it will have less penetration, but cause a larger hole on the inside which will result in a massive spalling. In 1954, during the siege of Dien Bien Phu , France had dismantled and flown in a number of M24 Chaffee light tanks. Their thickest armor was only 25.4 mm. The Viet Minh's main infantry antitank weapon

1080-411: The first of two safeties by moving the firing rod cocking lever (located on the left side) forward and then over the top to the right side. The gunner takes aim, while at the same time holding down the red safety lever located in front of the cocking lever, and then fires by pressing forward the red firing button with his right thumb. Both the red safety lever and the firing button must be pressed down at

1120-416: The interior of the vehicle's armour plate. A problem with shaped charge warheads is that if the ogive shaped liner is deep, the warhead will have more penetration but will form a smaller hole; smaller holes are associated with less damage inside the armoured vehicle than larger ones. Research on shaped charge warheads has shown a hole that is the size of a large coin on the outside of a tank turret will have

1160-616: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=AT-4&oldid=764296508 " Category : Letter–number combination disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages AT4 The AT4 is a Swedish 84 mm (3.31 in) unguided, man-portable, disposable, shoulder-fired recoilless anti-tank weapon manufactured by Saab Bofors Dynamics (formerly: FFV Ordance, later, Bofors Anti-Armour Systems). The AT4

1200-544: The open, and light armour. It can be set to detonate on impact or with a brief detonation delay. The heavier nose cap allows either to penetrate light walls or windows before exploding, or to be "skipped" off the ground for an air burst. For use against light armour, there is a smaller-cone HEAT warhead with 15 centimetres (5.9 in) penetration of RHA. High penetration (HP) – Extra high penetration ability, up to 42–60 centimetres (17–24 in) of RHA. Anti-structure tandem-warheads (AST) – Designed for urban warfare where

1240-469: The original 290 m/s to 220 m/s as part of its effort to be user-safe in a confined space, making the AT4-CS version more difficult to use as the drop is more pronounced. The effectiveness of the HEAT warhead is not dependent on speed. To fire, the gunner first removes the safety pin located at the rear of the tube, which unblocks the firing rod. They then take a firing position, ensuring that no one

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1280-430: The rear of the tube. When released, the firing pin strikes a primer located in the side of the casing's rim. The disadvantage of the recoilless design is that it creates a large back blast area behind the weapon, which can cause severe burns and overpressure injuries to friendly personnel in the vicinity of the user and sometimes even to the users themselves, especially in confined spaces. The back blast may also reveal

1320-412: The same time to fire the AT4. The red firing button has a similar resistance to the trigger pull of a rifle, so the gunner does not have to jab at the firing button, which could throw their aim off. After firing, the AT4 is discarded. Gunners are often trained to break off the sights after use, in order to prevent other soldiers from mistaking used launchers for unused ones. Unlike the heavier Carl Gustaf,

1360-577: The simplicity and durability of the tested version of the AT4, the US Army saw some room for improvement, specifically the addition of rear and front bumpers on the launch tube and changes to the sights and slings. After these changes, the AT4 was adopted by the US Army as the Lightweight Multipurpose Weapon M136. The Swedish Army also recognized these improvements and subsequently adopted the Americanized version of

1400-544: The standard HEAT projectile is replaced with the bunker-busting warhead developed for the Mk 153 Shoulder-Launched Multipurpose Assault Weapon (SMAW). No orders were ever placed. AT12-T – In the early 1990s, there were tests of a tandem charge 120 mm version (Bofors AT 12-T). The 14 kg weapon had a claimed penetration of 90 centimetres (35 in) RHA, and in 1994 was demonstrated to defeat two NATO Single Heavy targets inclined at 68 degrees from vertical with ERA, for

1440-402: The subject are speculative. Tests conducted by the U.S. Army on the AT4 confirmed that the claims made by FFV regarding the AT4's devastating post-penetration effect were substantially correct. As described by FFV in their first AT4 brochure in 1983, the beyond-armour effect had five distinctive characteristics upon penetration of an armoured vehicle: FFV claims that besides the effect of

1480-480: The user's position to the enemy. The problem of back blast was solved with the AT4-CS (Confined Space) version, specially designed for urban warfare . This version uses a saltwater countermass in the rear of the launcher to absorb the back blast; the resulting spray captures and dramatically slows down the pressure wave, allowing troops to fire from enclosed areas. The AT4-CS version also reduced its muzzle velocity from

1520-509: Was designed as a weapon to engage medium-to-light armoured vehicles from any direction or MBTs from the sides or rear, and as an assault weapon effective against buildings and fortifications. FFV's prime design goal was a weapon that was simple to use, rugged, and far more accurate against moving targets than previous individual antiarmour weapons. Another key requirement was that the AT4 not only be able to penetrate armour, but also exhibit devastating beyond-armour effect after penetration. FFV and

1560-409: Was studied by the engineers at FFV working on a replacement for the Pansarskott m/68 in the late 1970s. The result was the AT4 with a HEAT warhead that had, as the early AT4 brochures stated, a "special beyond-armour effect". The designers of the AT4's warhead intended that one hit would cause massive damage to both the occupants and the interior of the targeted vehicle. FFV has said very little about

1600-530: Was the old World War Two U.S. 2.36-inch bazooka , captured from Nationalist Chinese forces and supplied by Communist China . During the siege the French launched counterattacks using the M24 in support of their infantry. One Chaffee took seven hits from 2.36-inch bazookas and still continued to fight, demonstrating that portable rocket launchers were hardly a flawless tank-killer. Other examples became evident during

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