M60 machine gun
||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (July 2009)|
|Machine Gun, 7.62 mm, M60|
M60 machine gun
|Type||General-purpose machine gun|
|Place of origin||United States of America|
|Used by||See Users|
Laotian Civil War
Cambodian Civil War
Persian Gulf War
War in Afghanistan
Cambodian–Thai border stand-off
Colombian armed conflict
Insurgency in the Philippines
2013 Lahad Datu standoff
|Weight||10.5 kg (23.15 lb)|
|Length||1,105 mm (43.5 in)|
|Barrel length||560 mm (22.0 in)|
|Caliber||7.62 mm (0.308 in)|
|Action||Gas-operated, short stroke gas piston, open bolt|
|Rate of fire||500–650 rounds/min (rpm)|
|Muzzle velocity||2,800 ft/s (853 m/s)|
|Effective firing range||1,200 yd (1,100 m)|
|Feed system||Disintegrating belt with M13 Links|
The M60, officially the United States Machine Gun, Caliber 7.62 mm, M60, is a family of American general-purpose machine guns firing 7.62×51mm NATO cartridges from a disintegrating belt of M13 links. There are several types of live ammunition approved for use in the M60, including ball, tracer, and armor-piercing rounds.
Introduced in 1957, it has served with every branch of the U.S. military and still serves with other armed forces. Its manufacture and continued upgrade for military and commercial purchase continues into the 21st century, though it has been replaced or supplemented in most roles by other designs, notably the M240 in U.S. service.
- 1 Overview
- 2 History
- 3 Design
- 4 Variants
- 5 Civilian versions
- 6 Users
- 7 See also
- 8 References
- 9 External links
The M60 is a belt-fed machine gun that fires the 7.62 mm NATO cartridge (.308 Winchester) commonly used in larger rifles. It is generally used as a crew-served weapon and operated by a team of two or three individuals. The team consists of the gunner, the assistant gunner (AG in military slang), and the ammunition bearer. The gun's weight and the amount of ammunition it can consume when fired make it difficult for a single soldier to carry and operate. The gunner carries the weapon and, depending on his strength and stamina, anywhere from 200 to 1000 rounds of ammunition. The assistant carries a spare barrel and extra ammunition, and reloads and spots targets for the gunner. The ammunition bearer carries additional ammunition and the tripod with associated traversing and elevation mechanism, if issued, and fetches more ammunition as needed during firing.
The M60 can be accurately fired at short ranges from the shoulder thanks to its design. This was an initial requirement for the design and a hold-over in concept from the M1918 Browning Automatic Rifle. It may also be fired from the integral bipod, M122 tripod, and some other mounts.
M60 ammunition comes in a cloth bandolier containing a cardboard box of 100 pre-linked rounds. The M60 uses the M13 ammunition link, a change from the older M1 link system with which it was not compatible. The cloth bandolier is reinforced to allow it to be hung from the current version of the feed tray. Historically, units in Vietnam used B3A cans from C-rations packs locked into the ammunition box attachment system to roll the ammunition belts over for a straighter and smoother feed to the loading port to enhance reliability of feed. The later models changed the ammunition box attachment point and made this adaptation unnecessary.
The M60 machine gun began development in the late 1940s as a program for a new, lighter 7.62 mm machine gun. It was partly derived from German guns of World War II (most notably the FG 42 and the MG 42), but it contained American innovations as well. Early prototypes, notably the T52 and T161 bore a close resemblance to both the M1941 Johnson machine gun and the FG 42. The final evaluation version was designated the T161E3. It was intended to replace the M1918 Browning Automatic Rifle and M1919A6 Browning machine gun in the squad automatic weapon role, and in the medium machine gun role. One of the weapons tested against it during its procurement process was the FN MAG.
The U.S. Army officially adopted the T161E3 as the M60 in 1957. The decision to adopt the M60 instead of foreign designs, like modified versions of the proven German MG42 or the still-unproven FN MAG, was largely due to strict Congressional restrictions requiring preference be given to the designs of US arms manufacturers (even if a superior design was available from foreign sources) primarily out of desire to avoid paying licensing fees, but also out of a strong bias in favor of domestic products.
The M60 later served in the Vietnam War as a squad automatic weapon with many U.S. units. Every soldier in the rifle squad would carry an additional 200 linked rounds of ammunition for the M60, a spare barrel, or both. The up-gunned M113 armored personnel carrier ACAV added two M60 gunners beside the main .50 caliber machine gun, and the Patrol Boat, River had one in addition to two .50 cal mounts.
During the Vietnam War, the M60 received the nickname "The Pig" due to its bulky size. Vietnam's tropical climate harshly affected weapons, and the M60 was no exception. Its light weight made the gun damage easily and critical parts like the bolt and op rod wore out quickly. Even so, soldiers appreciated the gun's handling, mechanical simplicity, and effective operation from a variety of firing positions. Navy SEALs used M60s with shorter barrels and no front sights to reduce weight further. Some SEALs had feed chutes from backpacks to have a belt of thousands of rounds ready to fire without needing to reload.
In the 1980s, the M60 was partially replaced by the M249 Squad Automatic Weapon within Army infantry squads. Their new doctrine with the weapon reduced the general purpose machine gun role in favor of portability and a greater volume of fire. Soldiers disliked the new strategy, as even though the lighter SAW made movement faster, in firefights the larger 7.62 mm round is preferred. In defensive roles, the M60 has better accuracy and a longer range to keep the enemy back. The M60 was retained in the vehicle mounted role and the general-purpose role due to its greater power and range compared to the 5.56 mm M249.
In U.S. Marine Corps service, concerns about the M60's reliability, weight, and the high round counts of many M60s in service prompted the adoption of the M60E3 to replace most original M60s in infantry units. The M60E3 was five pounds lighter than the original M60. It included a forward pistol grip and had the bipod mounted to the receiver rather than the barrel. The weapon still was not durable and its performance was reduced.
In the early 1990s, Saco addressed Navy Special Warfare requirements to develop a retrofit parts package for the machine gun. Called the M60E4, it was more reliable and durable than the M60E3, had a “duckbill” flash suppressor, and a shorter and thicker positive lock gas cylinder extension. NAVSPECWAR units began to receive it in late 1994, when it was designated the MK43 Mod 0.
In January 1994, the U.S. Army began the Medium Machine Gun Upgrade Kit program. The only two competitors were M60 and M240 versions. Saco offered an "enhanced" M60E3 with product improved parts and FN offered its M240 coaxial gun with a buttstock, bipod, and other infantry features. As such, both weapons were upgrade kits of weapons already in service. 18 guns of each were tested until December 1995. There were two main performance areas: Mean Rounds Between Stoppages (MRBS-jams) and Mean Rounds Between Failures (MRBF-parts breaking). 50,000 rounds were fired through both guns. The M60 had 846 MRBS and 1,669 MRBF, compared to the M240's 2,962 MRBS and 6,442 MRBF. As a result, the M240 was declared the winner and accepted into infantry service. Although the M60 was lighter, had better balance, was more controllable, and there were many in the inventory, it did not work reliably enough.
Starting with Ranger Battalions, the U.S. Army began adopting and modifying M240 variants to replace their remaining M60s in the early 1990s. The M240 is several pounds heavier than the M60, and has a longer barrel and overall length, but it is more reliable in use and testing. However, the M60 uses a much simpler gas system that is easier to clean when care is taken during reassembly. This advantage is obviated since the gas tube is wired shut with lockwire to prevent the weapon from disassembling itself from vibration in hard use.
The M60 continues to be used in the 21st century by U.S. Navy SEALs and as a door gun on U.S. Army helicopters. It was the main 7.62 mm machine gun by some U.S. special operations forces to the late 1990s. As of 2005, it is used by the U.S. Coast Guard, U.S. Navy, and some reserve units. The M60 is generally being phased out.
The M60 is a gas-operated, air-cooled, belt-fed, automatic machine gun that fires from the open-bolt position and is chambered for the 7.62 mm NATO cartridge. Ammunition is usually fed into the weapon from a 100-round bandolier containing a disintegrating, metallic split-link belt.
The design drew on many common concepts in firearms manufacture of the period, such as stamped sheet metal construction, belt feed (a modified mechanism for belt feed from the MG42 with a single pawl), quick barrel replacement, a pistol grip and stock, and a Semi bullpup design similar to the FG42 (much of the action occupies the weapon's stock). The M60's operating system of an operating rod turning a rotating bolt was inspired by the FG42, which was based on the much earlier Lewis Gun. The M60 was even constructed with a secondary assisting firing pin spring that is used in the FG42 in semi-automatic mode even though it is actually unnecessary in the M60 (which operates only in full automatic mode). The M60's gas operation is unique, and drew on technical advances of the period, particularly the White "gas expansion and cutoff" principle also exploited by the M14 rifle. The M60's gas system was simpler than other gas systems and easier to clean.
The M60 was designed for mass production, just like the MG42 it was based on. While the M1919 required much machining for its large, recoil operated internal mechanisms, the M60's stamped sheet receiver had a gas operated, carrier-cammed bolt mechanism; the same type of mechanism was used on the Lewis machine gun.
The straight-line layout allowed the operating rod and buffer to run directly back into the buttstock and reduce the overall length of the weapon.
As with all such weapons, it can be fired from the shoulder, hip, or underarm position. However, to achieve the maximum effective range, it is recommended that a bipod-steadied position or a tripod-mounted position be used and fired in bursts of 3–5 rounds. The weapon is heavy and difficult to aim when firing without support, though the weight helps reduce the felt recoil. The large grip also allowed the weapon to be conveniently carried at the hip. The gun can be stripped using a live round of ammunition as a tool.
The M60 is often used with its own integrated bipod or with the M122 tripod. The M60 is considered effective up to 1,100 meters when firing at an area target and mounted on a tripod; up to 800 meters when firing at an area target using the integral bipod; up to 600 meters when firing at a point target; and up to 200 meters when firing at a moving point target. United States Marine Corps doctrine holds that the M60 and other weapons in its class are capable of suppressive fire on area targets out to 1,500 meters if the gunner is sufficiently skilled.
Originally an experimental M91 tripod was developed for the M60, but an updated M2 tripod design was selected over it which became the M122. The M122 would be itself replaced in the 2000s (decade) by a new mount, in time for the M60 to also be used with it.
The M60 family of weapons are capable of firing standard NATO rounds of the appropriate caliber. Most common in U.S. use are M61 Armor piercing, M62 Tracer, and M80 Ball. For training purposes, M63 Dummy and M82 Blanks are used. The new tungsten cored M993 Armor-piercing rounds may also be fired in the M60 as well, though they did not enter the inventory until after the M60 was withdrawn from service in active-duty units.
When firing blanks, the M13 or M13A1 blank-firing adaptor (BFA) is necessary in order to produce enough gas pressure to cycle the weapon with blanks. All ammunition must be fixed in a NATO standard M13 disintegrating metallic split-link belt to feed into the weapon.
The standard combat ammunition mix for the M60 consists of four ball (M80) cartridges and one tracer (M62) in belts of 100 rounds. The four to one ratio theoretically allows the gunner to accurately "walk" the fire into the enemy. Tracer bullets do not fly quite the same trajectory as ball and weapon's sights must be used for accurate fire—particularly at ranges in excess of 800 meters, where 7.62x51mm NATO tracer bullets usually burn out and are no longer visible. This is a problem for all weapons in this caliber using this tracer round.
|This section needs additional citations for verification. (February 2013)|
At the time of the M60's development, other designs, like the still unproven Belgian FN MAG and the proven German MG1 (MG42 derivative) had yet to enter production. In Army tests, the M60 proved fairly effective, but in the jungles of Southeast Asia in which it was soon used, it displayed a number of troubling issues.
A common complaint was the weapon's weight; though M60 was among the lightest 7.62 mm machine guns of the era, the weapon was poorly balanced, and thus awkward to carry for long periods. The single most common complaint was that the M60 was unreliable in extreme conditions and prone to jamming and other malfunctions during heavy firing, especially when it was dirty. The humidity and mud of the jungles combined with powder fouling and grease/oil in the action of the M60 to produce severe stoppages unless kept dry and thoroughly cleaned with solvent after each engagement, a difficult proposition for many units. The M60 did best in aerial and static-defense roles where it could be stored in controlled conditions and regularly maintained by skilled personnel. US Marines especially disliked the M60 and were among the last units to be issued the weapon; many Marine units held onto their BARs in the squad automatic weapon role until 1967–68 officially, and longer unofficially.
The M60 sometimes (depending on the version) tore the rims off from fired cartridge cases during the extraction cycle, causing a jam that required a cleaning rod be rammed down the barrel to extract the torn cartridge, a potentially deadly procedure while under fire in combat. The barrel latch mechanism (a swinging lever) could catch on the gunner's equipment and accidentally unlatch, causing the barrel to fall out of the gun. On new M60s, the lever was replaced with a push button mechanism that was less likely to be accidentally released, but few of the older M60s were modified due to expense, with many of the extant weapons still bearing them.
The grip/trigger housing assembly is held in place with a rather fragile leaf spring clip instead of the captive pins used in other designs. The spring clip has been known to be prone to breakage since the first trials at Aberdeen Proving Ground. Duct tape and cable ties have been seen on M60s in the field, placed there by their crews in case the spring clip breaks. The sear in the trigger mechanism gained a reputation for wearing down and a malfunction could cause the gun to "run away". A second sear notch was eventually added to the operating rod to reduce the chance of this happening.
Several critical parts of early production M60s, such as the receiver cover and feed tray, were made from very thin sheet metal stampings and were prone to bending or breaking; sturdier parts were eventually available in the early 1970s. Early M60s also had driving spring guides and operating rods that were too thin and gas pistons that were too narrow behind the piston head (part of an attempt to save weight), leading to problems with breakage. Metallurgical problems also played a part, (blamed by some on low-bid contractors), but after 1970 a slightly heavier part was designed and slowly put into the supply chain. High-round-count weapons were also susceptible to stretching of the receiver and other parts.
Another major criticism of the M60 was the inseparability of the barrel from the gas system regulator and the bipod. The sole advantage of the fixed regulator was preventing the operator from inadvertently damaging the weapon by setting the gas pressure too high, though this actually proved to be a major disadvantage in combat; the lack of an adjustable regulator also prevented the gunner from combating progressive fouling of the gas system by increasing the pressure to compensate. The result was insufficient gas power to operate the action after lengthy periods of fire, a situation only remedied by a full field strip of the weapon and cleaning the gas system with solvent and pipe cleaners, a virtually impossible procedure in a combat environment. The non-adjustable front sight is welded to the barrel, causing the weapon's sight calibration ("zero") to be ruined every time a barrel was changed. This design error was recognized early in the weapon's service, but was ignored due to financial reasons; every barrel in service would have needed to be replaced, and given the cost involved, the Department of Defense decided the loss in accuracy was comparatively unimportant given the weapon's role.
Perhaps the most convoluted and unnecessarily complex aspect of the M60 was the quick barrel change procedure, a critical aspect to any machine gun used for suppressive fire. Although equipped with the same quick change lever as the MG-42, each barrel on the M60 had a permanently mounted bipod and no carrying handle to grasp during combat barrel changes. The gunner was thus forced to come out of his prone supported firing position, retract the bipod, lay the entire weapon on the ground and don a large asbestos glove before he could even begin to handle the red-hot barrel to remove it. No other machine gun in history used such a cumbersome system; this system caused the M60 to take far longer to change barrels than other comparable GPMGs. The predictable loss of the glove under combat conditions was also a consistent problem.
The U.S. rejected the improved M60E3 and adopted the M240—a licensed version of the FN MAG—as their standard general purpose machine gun in 1995; this followed torture tests in which the veteran MAG proved more reliable than the M60E3 of the late 1980s that was designed specifically to fix the original design's reliability flaws. The U.S. Navy special operations forces continued to use the M60E3 for years because of its portability and low weight for its caliber, with a number of upgrades, including a change in feed system and barrel configuration, and fitted with optical sights and other modern accessories.
The nomenclature M60 describes either the first adopted version or, generically, the family of weapons derived from it.
Major variations include the M60E1 (an improved version that did not enter production), the M60E2 (a version designed to be used from fixed mounts as a co-axial for armored vehicles or in helicopter armament systems), the M60E3 (a lightweight version) and the M60E4 (another improved version, designated Mk 43 Mod 0 by the U.S. Navy).
The M60C was adopted for use on fixed mounts on aircraft. It was characterized by the use of an electric solenoid to operate the trigger and a hydraulic system to charge the weapon. The M60D differed from the base model by employing spade grips, a different sighting system, and lacking a forearm. It was typically employed as a door gun on helicopters or as a pintle mounted weapon as on the Type 88 K1 tank.
There are many smaller variants among each type, between makers of the firearm, and over time.
- T161: The M60's developmental designation before it was type-classified in the 1950s.
- M60: The basic model, type-classified in 1957.
- M60E1: An improved version that did not enter production. The primary difference was the handle fixed to the barrel and the removal of the gas cylinder and bipod from the barrel assembly.
- M60E2: Used in vehicles as a coaxial machine gun; electrically fired.
- M60B: Used in helicopters in the 1960s and 1970s; unmounted.
- M60C: Used in fixed mounts in aircraft in the 1960s and 1970s; electrically fired and hydraulically charged.
- M60D: Replaced the M60B; a pintle-mounted version used especially in armament subsystem for helicopters, but also some other roles.
- M60E3: An updated, lightweight version adopted in the 1980s.
- M60E4 (Mk43 Mod 0/1): An improved model of the 1990s that looks similar to the E3, but has many improvements. It has subvariants of its own, and is also used by the U.S. Navy (as the Mk 43 Mod 0/1). The Mk 43 Mod 1 is a specialized version with additions such as extra rails for mounting accessories.
- M60E6: A lightened and improved version of the M60E4.
The initial version was officially adopted by the U.S. Army in the late 1950s, though at this time it was only intended for the infantry. It was known as the T161 before it was adopted (specifically the T161E3), and was chosen over the competing T52 during testing in the 1950s. They both used a similar feed and were both gas-operated, but the T161 was easier to produce and its different internals performed better. The model that won the competition was the T161E3.
The model was type-classified in 1957, and entered production. It saw its first heavy use in the 1960s. The basic design has undergone some smaller changes, and has been produced by different manufacturers.
The M60E1 was the first major variant of the original M60. It did not go into full-scale production, though many of its features were included into the later E3 and E4 variants. Some of its features were also incorporated into the existing M60 production. This mainly changed how the gas cylinder, the barrel, and the bipod were connected; in the first iteration. The M60 and the M60E1 are two different versions. Opinions are varied on whether the M60E1 was officially adopted or not.
One of the more noticeable changes on the M60E1 is that the bipod attachment point was moved to the gas tube rather than the barrel (like on the later M60E3). It did not, however, have a forward pistol grip, as was added on the E3.
The M60E2 is used on armored fighting vehicles, such as the M48A5, later M60 Patton versions and the K1 Type 88. It lacks many of the external components of the standard M60, including stock and grips. The M60E2 was electrically fired, but had a manual trigger as a backup, as well as a metal loop at the back for charging. The gas tube below the barrel was extended to the full length of the weapon to vent the gas outside the vehicle. This version achieved a mean time between failures of 1,669 during testing in the 1970s..
The M60B was a short-lived version designed to be fired from helicopters, with limited deployment made in the 1960s and 1970s. It was not mounted, just held, and was soon replaced by the pintle-mounted M60D. The 'B' model differed most noticeably in that it had no bipod and featured a different rear stock than the regular model. It still had a pistol grip (as opposed to spade grips). The M60B's advantage over pintle-mounted variants was that it had a wider and much less restricted field of fire.
The M60C is a variant of the standard M60 for aircraft-mounting, such as in helicopter armament subsystems. It lacks things like the bipod, pistol grip, and iron sights. The main difference between the standard M60 and the "C" variant is the electronic control system and the hydraulic swivel system used. It could be fired from the cockpit by the pilot or co-pilot. It is an electronically controlled, hydraulic-powered, air-cooled, gas-operated, belt-fed weapon system. It used the M2, M6, and M16 armament subsystems and was mounted on the OH-13 Sioux, the OH-23 Raven, the UH-1B Huey, and comprised the standard fixed armament of the OV-10 Bronco. M60C production was on the order of several hundred. It was also used in the XM19 gun pod.
The M60D is a mounted version of the standard M60. It can be mounted on boats, vehicles and as a pintle-mounted door gun in helicopters. When used in aircraft, it differs from the M60C in that it is not controlled by the pilot—rather, it is mounted in a door and operated by a member of the crew. Like the rest of the M60 family, it is an air-cooled, gas-operated, belt-fed weapon. Unlike other models, however, the M60D normally has spade grips and an aircraft ring-type sight or similar, as well as an improved ammunition feed system. A canvas bag is also affixed to the gun to capture ejected casings and links, preventing them from being sucked into the rotor blades or into an engine intake. The M60D was equipped on the UH-1B Huey (using the M23, XM29, M59, and the Sagami mounts), the CH-47 Chinook (using the M24 and M41 mounts) in both door and ramp locations, the ACH-47A "Guns-A-Go-Go" variant of the Chinook (using the XM32 and XM33 mounts), and on the UH-60 Black Hawk (using the M144 mount). The M60D is also used by the British on Royal Air Force Chinooks. In US service, the M60D has been primarily replaced by the M240H. The M60D is still manufactured by U.S. Ordnance and still used on the SH-60 Seahawk.
The M60E3 was fielded c. 1986 in an attempt to remedy problems with earlier versions of the M60 for infantry use. It is a lightweight, "improved" version intended to reduce the load carried by the gunner. Unlike its predecessors, the M60E3 has several updated modern features. It has a bipod (attached to the receiver) for improved stability, ambidextrous safety, universal sling attachments, a carrying handle on the barrel, and a simplified gas system. However, these features also caused almost as many problems for the weapon as they fixed. There were different types of barrels used, but the lightweight barrel was not as safe for sustained fire at 200 rounds per minute as heavier types. However, some personnel claim to have witnessed successful prolonged firing of the weapon. The stellite superalloy barrel liner makes it possible, but the excessive heat generated by this process can quickly make the gun unusable. There were two main barrels, a lightweight barrel and another heavier type—the former for when lighter weight was desired, and the latter for situations where more sustained fire was required.
The reduced-weight components also reduced the durability of the weapon, making it more prone to rapid wear and parts breakage than the original. Most infantry units in the U.S. Army and Marine Corps have now switched over to the M240 as their general-purpose machine gun, which is more reliable (particularly when dirty) and seems to be well liked by the troops for its ruggedness, despite the fact that it weighs 27.6 lb (12.5 kg) compared to the standard M60 at 23.15 lb (10.5 kg).
The U.S. Air Force Security Forces received the M60E3 from 1988 to 1989. All USAF M60E3s were withdrawn from general issue by 1990, because it did not meet the vehicle mount requirements of the Cadillac Gage Ranger and due to overheating problems. The M60E3 did remain in the Air Force as an emergency issue weapon only. The Air Force cut the barrel change times, sustained fire 100 rounds per minute change barrel every 10 minutes (M60) to five minutes (M60E3), and rapid fire 200 rounds per minute change barrel every five minutes to two minutes.
M60E4/Mk43 Mod 0/1
The Mk43/M60E4 General Purpose Machine Gun (GPMG) is a 7.62 mm NATO light machine gun. Evolved from the M60 Series of machine guns, it has several improvements over the originals. The Mk43/M60E4 Series includes the Mod 0 and Mod 1 configurations.
The Mk43/M60E4 is effective against infantry, unarmored or lightly armored vehicles and boats. It is the primary light machine gun used in some NATO countries and other U.S. Government export-approved countries. The Mk43 machine gun currently is manufactured solely by U.S. Ordnance (USORD). USORD has produced it since 2000.
This firearm is the most modernized and latest in the generations of the old M60 family and incorporates a number of improvements over past versions. Externally, it looks somewhat like the M60E3, but it has many internal changes and improvements that modernize the effectiveness and reliability of this weapon. In general it is a more reliable weapon than all previous M60s. Externally, it features a different forward grip, iron sights, butt stock and bipod. The M60E4/MK 43 has higher pull for the belt, and is available in a variety of configurations. Older M60 models can be upgraded with a conversion kit manufactured by U.S. Ordnance to the M60E4/MK 43. The M60E4/MK 43 were primarily developed in the 1990s and have continued to be redeveloped in the 2000s (decade). Early MK 43s had some distinct differences from the E4 (such as a duckbill flash suppressor), though by the 2000s (decade) these distinctions seemed to have ended.
The Navy has designated this weapon as the MK 43 Mod 0. It was developed for the U.S. Navy SEALs to replace their existing stock of M60E3 machine guns fitted with shorter "assault barrels". These weapons are identical to standard M60E4s, with the exception of the barrel length, and can be used either as suppressive fire or direct fire weapons. The MK 43 Mod 1 adds significantly more rail attachment points to the weapon's receiver cover and handguard.
U.S. Ordnance website states in their FAQ, as of 2005, that the "M60E4 and the MK 43 are the same weapon system". The M60E4 and MK 43 versions in the past were roughly similar, although they are part of the same family. While it might be fair to say that the Mk 43s are a type of M60E4, there are technical differences between any given M60E4 model. Early MK 43s have certain differences over M60E4 from the same period, the most obvious being the duck-bill flash hider and different handguard. This difference is no longer seen on the current MK 43s still manufactured by U.S. Ordnance.
In Army trials during the 1990s the M60E4 produced by Saco Defense was pitted against the (then called) M240E4 produced by FN for a new medium machine gun to be used by the infantry. The competition was to replace the decades-old M60s. The M240E4 won, and was then classified as the M240B. While the M240B had been more reliable in the tests, it was noted to be a heavier weapon than the M60E4.
The M60E4/MK 43 is a modern update to the entire series, such that it is also available in many of the previous configurations, such as a co-axial weapon. Kits are offered to convert older models to the E4 standard.
- M60E4 (Light machine gun):
- Short barrel: weight: 22.5 lb (10.2 kg); length: 37.7 in (95.8 cm)
- Long barrel: weight: 23.1 lb (10.5 kg); length: 42.4 in (108 cm)
- Assault barrel: weight: 21.3 lb (9.66 kg); length: 37.0 in (94.0 cm)
- Width: 4.8 in (12.2 cm)
- M60E4 (mounted):
- Length: 43.5 in (110 cm)
- Width: 5.9 in (15.0 cm)
- Weight: 22.7 lb (10.3 kg)
- M60E4 (co-axial):
- Length: 42.3 in (107 cm)
- Width: 4.8 in (12.2 cm)
- Weight: 21.2 lb (9.62 kg)
The Mk43/M60E4 is a gas-operated, disintegrating-link, belt-fed, air-cooled machine gun that fires from an open bolt. It is the newest, upgraded version of the M60 Series machine guns.
The Mk43/M60E4 fires a 7.62 × 51 mm NATO cartridge, which offers accuracy, reliability, and stopping power. It fires at a cyclic rate of 500 to 600 rounds per minute, with an effective distance of 1200 yards (1100 meters). The weapon’s controllable, yet lethal, rate of fire allows for accurate firing in the standing, kneeling and prone positions.
The machine gun’s light weight—20 to 21 pounds (9 to 10 kilograms)—and compact design make it easy to carry long distances and maneuver in tight spaces. It also allows for the weapon to be fired from the shoulder accurately.
The M60E4/Mk43 Mod 0, typically used as an infantry machine gun, features an injection-molded composite handguard. The weapon system’s quick-change barrel is crucial for safety and efficiency, particularly when the operator is under fire. With the lightweight bipod mounted to the receiver, the barrel can be changed without removing the bipod.
The M60E4/Mk43 Mod 1 has multiple M1913 rail mounting points for mounting optics, aiming lasers, and accessories for around-the-clock capability. It mounts directly or adapts to all standard NATO tripod and vehicle mounts.
Barrels are Stellite lined for sustained fire and extended life. They are available in short, long and heavy fluted configurations for use in various applications. All major components of the Mk43/M60E4 directly interchange with other M60 configurations. U.S. Ordnance manufactures a conversion kit that upgrades older M60s to its Mk43/M60E4 model.
Source: U.S. Ordnance Spec Sheets
An improvement on the M60E4, this weapon won the Danish Army's GPMG replacement program. The weight has been reduced to 9.27 kilograms, while changes to the rail system and bipod have been made. A significant number of internal improvements have also increased reliability. 
5.56 mm derivatives
Scaled down derivatives of the M60 machine gun also existed as the Ford Aerospace XM234 and Rodman Laboratories XM235 as a replacement for the M1918 Browning Automatic Rifle. Both weapons lost to the FN Minimi.
A number of semi-automatic versions for the civilian market have been produced in the United States. The internals must be extensively modified to make it essentially impossible to convert them to fully automatic weapons. If the design is approved by the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE), they are treated as belt-fed semi-automatic rifles; however, individual state and local regulations still apply.
The U.S. Ordnance company is the current maker authorized by Saco to produce mil-spec M60s and M60 parts. However, U.S. Ordnance put its civilian semi-auto sales on hold until 2006 because its production capacity is required for government orders. The company had charged $8000 for a new semi-automatic M60.
The Desert Ordnance company is a current maker of M60s and M60 parts. The company charges between $13,000–$14,000 for a new semi-automatic M60, depending on the model.
Various makes of older fully automatic versions are on the market as well, but there are many legal requirements to be met before purchasing them, and they cost upwards of U.S. $20,000–30,000. This is largely due to the restriction on the production of fully automatic firearms in the U.S. for the general civilian market since 1986. The combination of banning production and importation has led many to think it is illegal to own a machine gun, when, in fact, it is legal to own and use a fully automatic M60 machine gun in the United States (unless prohibited by other state or local laws).
- Australia: Replaced by the FN Minimi (light roles) and FN MAG (general-purpose roles).
- Brazil
- Costa Rica
- Czech Republic: The M60E4 is used in small numbers by specialized units of the Czech Army. Known to be in use by the 601st Special Forces Group in 2006 to replace the UK-59L.
- Democratic Republic of Congo
- Dominican Republic
- El Salvador
- Lithuania: Received a grant of 75 M60s in 2002 from the USA's "Defense Logistics Agency". 
- Luxembourg: In service 1957–1972; replaced by FN MAG.
- Malaysia: M60E3 is used by the Malaysian Army Grup Gerak Khas.
- Poland: Polish Navy: Limited number were acquired along with Oliver Hazard Perry-class frigate.
- Portugal: Portuguese Army uses M60E and D mounted on V-150 Commando.
- Republic of Korea: Produced under license since 1974.
- Saint Vincent and the Grenadines
- Senegal: Received a grant of 2,500 M60s in 2002 from the USA's "Defense Logistics Agency". 
- Taiwan: Produced locally.
- Trinidad and Tobago
- United Kingdom: Used by the Royal Air Force; mounted on the Chinook.
- United States: Used by the US Army and the US Navy SEALs.
- PK machine gun, M60's Warsaw Pact counterpart.
- List of individual weapons of the U.S. Armed Forces
- List of crew-served weapons of the U.S. Armed Forces
- The M60. Federation of American Scientists.
- "Modern Firearms – M60". Retrieved March 06, 2012.
- Norman Polmar (15 January 2005). The Naval Institute guide to the ships and aircraft of the U.S. fleet. Naval Institute Press. p. 500. ISBN 978-1-59114-685-8. Retrieved 2 November 2011.
- Weapons: An International Encyclopedia From 5000 B.C. To 2000 A.D. Diagram Visual, p. 217. ISBN 0-312-03950-6.
- "Army's Newest Machine Gun Shoots from the Shoulder." Popular Science, September 1957, pp. 122–123.
- M. Zachary Sherman; Zachary M. Sherman (1 January 2011). Fighting Phantoms. Capstone Press. p. 41. ISBN 978-1-4342-2560-3. Retrieved 2 May 2011.
- Life and Times of the M60 - SAdefensejournal.com, 10 August 2011
- The World Encyclopedia of Rifles and Machine Guns, pp. 93, 196.
- The World Encyclopedia of Rifles and Machine Guns, p. 93
- Jane’s Infantry Weapons, Sept. 2009
- "Gun Control : Machine Guns". Guncite.com. 2005-02-19. Retrieved 2009-07-06.
- "Profiling the Small Arms Industry".
- Jones, Richard D. Jane's Infantry Weapons 2009/2010. Jane's Information Group; 35 edition (January 27, 2009). ISBN 978-0-7106-2869-5.
- Gander, Terry J.; Hogg, Ian V. Jane's Infantry Weapons 1995/1996. Jane's Information Group; 21 edition (May 1995). ISBN 978-0-7106-1241-0.
- GRAND-DUCHY OF LUXEMBOURG
- Thompson, Leroy (December 2008). "Malaysian Special Forces". Special Weapons. Retrieved 2010-05-20.
- William Shaw (September 1984). "South Korean Foreign Military Sales Program". Library of Congress. p. 9.
- Miller, David (2001). The Illustrated Directory of 20th Century Guns. Salamander Books Ltd. ISBN 1-84065-245-4.
- M60E3 & Mk43 Mod 0
- The M60E3 at GlobalSecurity.org
- Modern Firearms & Ammunition: the M60
- Department of the Army Field Manual No. 3-22.68 at GlobalSecurity.org
- U.S. Army TACOM — Rock Island
- MCWP 3–15.1 United States Marine Corps: "Machine Guns and Machine Gun Gunnery"
- Navy SEALs
-  U.S. Ordnance MK43 MOD 0
|Wikimedia Commons has media related to:|
- US Ordnance Website (Current maker of M60's, M60D, MK43/M60E4)
- Saco Defense Systems M60 E at the National Firearms Museum.
- Military Factory Small Arms
- US Army manual: Operator's Manual For M60, M122, M60D
- Operator's Manual
- "M60 Machine Gun, 7.62mm - Operation and Cycle Of Functioning" from 1960 on YouTube
- Bruce, Robert (Spring 2009). "New Life for a Combat Classic: US Ordnance MK43 Mod 1 Machine Gun". Small Arms Defense Journal: 66–71. The article includes a detailed list of the twenty-two improvements made over previous versions of the M60.
- Nazarian's Gun's Recognition Guide (FILM) M60 Presentation (.MPEG)