The M68 is an American

105 mm 1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. I ...

tank gun A tank gun is the main armament of a tank. Modern tank guns are high-velocity, large-caliber artilleries capable of firing kinetic energy penetrators, high-explosive anti-tank, and cannon-launched guided projectiles. Anti-aircraft guns can also ...

. It uses a British-designed L7 gun tube and cartridges with an American-designed mount, breech assembly and recoil mechanism.

Technical characteristics

The M68 differs from the L7 in several aspects : *The M68 uses a concentric recoil

spring Spring(s) may refer to: Common uses * Spring (season) Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of ...

instead of a separate buffer and recuperator

hydraulic cylinder A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment (engineering vehicles ...

s. *The M68 has a cylindrical breech with a vertical sliding

breech block A breechblock (or breech block) is the part of the firearm action that closes the breech of a breech loading weapon (whether small arms or artillery) before or at the moment of firing. It seals the breech and contains the pressure generated by t ...

instead of a square-shaped breech with a horizontal sliding breech block. *Firing is electrical only. *The M68

barrel A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, ...

is secured to the breech by a tapered pin and interrupted breech threads which allow the barrel to be removed from the gun shield without having to dismantle the mantlet. *The M68 is fitted with an eccentric

bore evacuator A bore evacuator or fume extractor is a device which removes lingering gases and airborne residues from the barrel of an armored fighting vehicle's gun after firing, particularly in tanks and self-propelled guns. By creating a pressure differe ...

instead of a concentric model in order to provide more clearance over the rear deck.

Models

*M68 : initial production variant, used on the original variant of the

M60 tank The M60 is an American second-generation main battle tank (MBT). It was officially standardized as the Tank, Combat, Full Tracked: 105-mm Gun, M60 in March 1959. Although developed from the M48 Patton, the M60 tank series was never officially ...

and the M116 gun mount. Retrofitted to the

M48A5 The M48 Patton is an American first-generation main battle tank (MBT) introduced in February 1952, being designated as the 90mm Gun Tank: M48. It was designed as a replacement for the M26 Pershing, M4 Sherman, M46 and M47 Patton tanks, and wa ...

. *M68E1 : variant used on the M60A1 and M60A3 tanks in mount M140. They were fitted with a

fiberglass Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth ...

thermal shroud in 1973. *M68A1 : improved variant built in 1980 for use on the M1 and IPM1 versions of the

M1 Abrams The M1 Abrams is a third-generation American main battle tank designed by Chrysler Defense (now General Dynamics Land Systems) and named for General Creighton Abrams. Conceived for modern armored ground warfare and now one of the heaviest ta ...

. The M68A1 features an

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

thermal shroud and a pad for fixing the muzzle reference sensor. *M68A1E4 : a light weight, low-recoil version of the M68A1 designed for the

M1128 Mobile Gun System The M1128 Mobile Gun System (MGS) is an eight-wheeled armored car of the Stryker armored fighting vehicle family, mounting a 105 mm tank gun, based on the Canadian LAV III light-armored vehicle manufactured by General Dynamics Land Systems for ...

(Stryker MGS). Also designated as M68A2, it features an

Ares Incorporated Ares Incorporated is an American weapons manufacturer and firearms engineering company co-founded by the American weapons inventor and developer Eugene Stoner in 1971. The company is based in Port Clinton, Ohio, and produces fire control systems, t ...

long stroke, low recoil impulse mechanism and a

muzzle brake A muzzle brake or recoil compensator is a device connected to, or a feature integral to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter recoil and unwanted ...

(later removed). The breech is mounted upside down to accommodate the automatic loader.

Foreign variants

*KM68A1 : licence-produced variant of the US M68A1 gun for the

South Korean Army The Republic of Korea Army (ROKA; ko, 대한민국 육군; Hanja: 大韓民國陸軍; RR: ''Daehanminguk Yuk-gun''), also known as the ROK Army or South Korean Army, is the army of South Korea, responsible for ground-based warfare. It is the l ...

. Used on the South Korean variant of the M48, the M48A5K and K1 tanks. *M68T : Turkish licence-built versions by MKEK under the designation of M68T to up-gun its 90 mm armed M48 fleet, took place in the 1980s. *M64 L71A : Israeli variant built by

IMI IMI may refer to: Companies and organizations * IMI plc, a British engineering company * IMI Systems, an Israeli weapons manufacturer * Indian Music Industry, a trust that represents the recording industry distributors in India * Indonesian Motor ...

for the

Merkava The Merkava ( he, מרכבה, , "chariot") is a series of main battle tanks used by the Israel Defense Forces and the backbone of the IDF's armored corps. The tank began development in 1970, and its first generation, the Merkava mark 1, entere ...

Mk. I and Mk. 2 tanks.

Prototypes

*T254E1 : US designation for the L7A1, it had the same horizontal sliding breech block as the L7 and used British X15/L52 barrels with a concentric bore evacuator on the barrel. *T254E2 : US variant of the T254, it had a vertical drop breech block with the X15E8 barrel and a concentric bore evacuator. Later standardized as M68. Used in

M60 Patton The M60 is an American second-generation main battle tank (MBT). It was officially standardized as the Tank, Combat, Full Tracked: 105-mm Gun, M60 in March 1959. Although developed from the M48 Patton, the M60 tank series was never officially ...

prototype vehicles. *T254E3 : US variant designed in 1975, identical to thee T254E2/M68 but with chrome-plated bores. Only two built. *XM24 : the XM24 gun tube was extended by compared to the M68A1 and it could tolerate a higher chamber pressure. Designed to replace the 105mm gun M68A1 in the M1 and the IPM1, it was expected to have improved penetration performance, particularly with the upcoming XM900 APFSDS (later cancelled and superseeded by the M900A1). At that time, it was expected that the installation of the enhanced 105 mm gun would be less costly than retrofitting the M1 and IPM1 with the 120 mm gun M256. The program was initiated in March 1983, the Watervliet Arsenal manufactured 14 XM24 tubes and 17 breeches for cannon during the

fiscal year A fiscal year (or financial year, or sometimes budget year) is used in government accounting, which varies between countries, and for budget purposes. It is also used for financial reporting by businesses and other organizations. Laws in many ...

1984. The

US Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

completed the advanced development phase in February 1984 and initiated it for the M1 in March. Full-scale development was expected to begin in November 1984 for the M60A3 and in January 1985 for the Abrams but the program was abandoned.

Usage

: M68A1 cannon used early production models (M1 and IPM1) *

M47 Patton The M47 Patton was an American main battle tank, a development of the M46 Patton mounting an updated turret, and was in turn further developed as the M48 Patton. It was the second American tank to be named after General George S. Patton, command ...

: in some upgraded variants **M47M: Iranian modification of US-supplied M47Ms **Sabalan: Iranian modification **

Tiam Datuk Wira Poh Ah Tiam (; April 1, 1952 – March 15, 2007) was a Malaysian politician, businessman and community leader of Chinese descent. Poh was born in Kampung Belimbing, near Durian Tunggal, Malacca. He and his family moved to nearby Ma ...

: Iranian modification *

M48 Patton The M48 Patton is an American List of main battle tanks by generation#First generation, first-generation main battle tank (MBT) introduced in February 1952, being designated as the 90mm Gun Tank: M48. It was designed as a replacement for the M2 ...

: in some upgraded variants **M48A5: US model **

Magach Magach (, " battering-ram") is the designation of a series of tanks in Israeli service. The tanks are based on the American M48 and M60 Patton tanks. The name continued to be used for all Patton tanks, including the M60. Magach 1, 2, 3, 4 and 5 ar ...

3: Israeli modification **

CM-11 Brave Tiger The CM-11 Brave Tiger () is a main battle tank (MBT) that was developed by the American General Dynamics and the Republic of China Army Armored Vehicle Development Center. It was introduced to the public on 14 April 1990. The CM-11 is a hybrid ...

: Taiwanese modification **

CM-12 Tank The CM-12 Tank is a modified M48A3 made for the Republic of China Army situated on Taiwan. The Armored Vehicle Development Center (AVDC) used the extra 100 fire-control system units from the production of the CM-11 Brave Tiger to modify the exi ...

: Taiwanese modification **M48A5K1: South Korean modification **M48A5T1: Turkish modification *

: M60 and M60A1 using M68, M60A3 using M68E1 *

: M68A1E4 cannon * Expeditionary tank * K1 Type 88: KM68A1 cannon *

: Mark I and Mark II models *

T-54/55 The T-54 and T-55 tanks are a series of Soviet main battle tanks introduced in the years following the Second World War. The first T-54 prototype was completed at Nizhny Tagil by the end of 1945.Steven Zaloga, T-54 and T-55 Main Battle Tanks ...

: in some upgraded variants ** Tiran-4Sh: Israeli modification of T-54, both L7 and M68 variants fitted ** Tiran-5Sh: Israeli modification of T-55, both L7 and M68 variants fitted ** Type 72Z: Iranian modernization of T-54/55 and Type 59 **

Ramses II Ramesses II ( egy, rꜥ-ms-sw ''Rīʿa-məsī-sū'', , meaning "Ra is the one who bore him"; ), commonly known as Ramesses the Great, was the third pharaoh of the Nineteenth Dynasty of Egypt. Along with Thutmose III he is often regarded as t ...

: Egyptian modernization of T-55

References