tank with the tank commander's .50-caliber
M2 Browning machine gun on the right side of the tank, and the ammunition loader's M240 on the left side of the tank. A second M240 (barely visible) is mounted coaxially next to the main gun
FN Herstal first introduced the MAG general-purpose machine gun in the early 1950s. The M240 is the US military's adoption of the
FN MAG. Parts compatibly of other MAG variants adopted by other NATO members are interchangeable. The M240 is part of the secondary armament on the U.S. Army M1 series Abrams tank, M2/M3 series Bradley Fighting Vehicle, and the U.S. Marine Corps LAV-25. The
M240E1 is the U.S. Marine Corps version of the original M240 coaxial/pintle-mounted machine gun that is used on vehicles like the LAV-25. It can also be fitted with spade grips for flexible use, like the ones from the M240D. The
M240C is the right-hand variant on the original coaxial (installed alongside the main machine gun) M240, it is identical to the M240 except for the ammunition cover and feed tray. It has a right-handed feed for use on the
M2/M3 Bradley Fighting Vehicle and LAV as the coaxial machine gun. It is fed from the left on the M1 Abrams and other M1 variant (M1A1, M1A2, M1A2 SEP) tanks. The M240C uses a charging cable instead of a charging handle, has a cut-off pistol grip and has a special paddle assembly that allows the trigger to be actuated by means of a solenoid. Since the machine gun is not meant to be handled during use, the barrel is fully exposed and must be handled with asbestos mittens during barrel changes. The rate of fire of the M240, M240E1, and M240C can be controlled by three different gas regulator settings; • The first setting allows the machine gun to have a cyclic rate of fire of around 650–750 rounds per minute, • The second setting allows the machine gun to have a cyclic rate of fire of around 750–850 rounds per minute, • The third setting allows the machine gun to have a cyclic rate of fire of around 850–950 rounds per minute.
M240D The M240D is an upgrade of the M240E1, primarily in the addition of an optical rail on the receiver cover. It has two possible configurations: aircraft and egress (ground). In the aircraft configuration, the M240D has a front and rear sight and a trigger group which accommodates the spade grip device, while the ground configuration involves the installation of an egress package or "infantry modification kit", which is designed to provide downed aircrew personnel with increased firepower. The egress package contains a buttstock assembly, a buffer assembly, a bipod assembly, and a conventional trigger assembly. The barrel assembly contains a three position gas regulator. The first setting allows the machine gun to cycle at 650–750 rounds per minute, the second gas setting allows the machine gun to cycle at 750–850 rounds per minute, and the third setting allows the machine gun to cycle at 850–950 rounds per minute. The aircraft configured M240D weighs 25.6 lb (11.6 kg) and is 42.3 in (1,074.42 mm) long, whilst the egress configuration weighs 26.2 lb (11.9 kg) and is 49 in (1244.6 mm) long.
M240H The M240H (formerly designated as the M240E5)
M240G -mounted M240G The M240G allows for commonality throughout the Marine Corps whether the machine gun is used in an infantry, vehicular, or airborne role. The M240G is the ground version of the original M240 or M240E1, 7.62 mm medium class machine gun designed as a coaxial/
pintle-mounted machine gun for tanks and LAVs. The M240G can be modified for ground use by the installation of an "infantry modification kit" (a
flash suppressor, front sight, carrying handle for the
barrel, a buttstock, infantry length pistol grip, bipod, and rear sight assembly). The M240G lacks a front heat guard, and as such is a few pounds lighter than the M240B, weighing in at . The rate of fire of the M240G can be controlled by three gas settings. On gas setting one the machine gun will fire at 650–750 rounds per minute, on gas setting two the machine gun will fire at 750–850 rounds per minute, and on gas setting three the machine gun will fire at 850–950 rounds per minute. The size of the gas port increases resulting in greater energy being delivered to the action. Use at high settings induces added stresses on the action and results in a shorter service life of the machine gun. It gives the operator an ability to adjust the gas bleed to the action. This also allows the machine gun to continue firing when very dirty from sustained use in combat conditions when it may be otherwise rendered inoperable due to an extremely dirty and dry action.
M240N The M240N is designed with a front and rear sights, and configured specifically for mounting on watercraft. It is similar to the M240G, but lacks the integral bipod. It also uses the hydraulic buffer of the M240B, and features the lower cyclic rate of fire of the M240B which is around 550–650 rounds per minute. The M60E4 (Mk 43 as designated by the Navy) was pitted against the M240E4 (former designation of the M240B) in the Army trials during the 1990s for a new infantry medium machine gun, in a competition to replace the decades-old M60s. The M240E4 won, and was then classified as the
M240B. This led to 1,000 existing M240s being sent to FN for an overhaul and a special kit that modified them for use on ground (such as a stock, rail systems, etc.). This led to procurement contracts in the late 1990s for the all-new M240B. However, a new feature was added, a hydraulic buffer system to reduce the felt recoil as incorporated in the M60. While the M240B had been more reliable in the tests, it was a few pounds heavier than the M60E4, which led to the development of the lighter
M240L. The Army M240 converted to the M240B configuration should not be confused with the large numbers of M240/E1 converted to the M240G configuration for the Marine Corps. The main differences between the M240B and M240G is the
Picatinny rail system, hydraulic buffer inside of the butt stock to reduce the amount of recoil felt by the gunner, and the number of gas settings on the gas regulator plug. The M240G has three gas settings, allowing the machine gun to have a fire rate between 650 and 750 rounds per minute when set to the first gas setting, 750–850 rounds per minute at the second gas setting, and 850–950 rounds per minute at the third gas setting, whereas the M240B only has one setting, restricting the fire rate to between 550 and 650 rounds per minute. The smaller gas port used on the M240B slows down the rate of fire, which increases the longevity of the machine gun by reducing stresses on the action. A side effect is a machine gun that will not fire when extremely dirty as the energy on the piston is reduced. The M240B is being tested with a new adjustable buttstock that may replace the current stock of the M240B. The lighter M240L has started to replace the M240B in U.S. Army service. The Marine Corps is observing the progress of the M240L, but feels it is too expensive for adoption. The Corps is instead looking to upgrade the M240 barrel through several ways, including carbon fiber coatings, new alloys, or ceramic liners, to lighten and strengthen the barrel. The goal would be a barrel that would not need to be changed, would weigh the same, but decrease heat retention, lessen warping, and eliminate cook-offs. They are also interested in incorporating a
suppressor into the barrel, rather than having to attach one, to reduce the sound of shots and make it difficult to determine where the gunner is located.
M240L The M240L (M240 Lima), formerly the M240E6 is the product of the M240B weight reduction program which reduces the weight of the existing M240B by . To achieve 18% weight savings, the M240L incorporates titanium construction and alternative manufacturing methods for fabricating major components. The resulting improvements reduced the soldier's combat load while allowing easier handling and movement of the machine gun. The M240L may replace the M240B in U.S. Army service. Titanium was used to make the receiver body, front sight post, and carrying handle while maintaining steel operating system components. Manufacture had to be adjusted because titanium takes longer to machine than steel and requires more frequent replacement of tooling bits; more pliable stainless steel rivets were used, and the receiver was coated with boron and chrome carbo-nitride coatings with a ceramic-based top coat to preserve it under extreme operating temperatures. The M240L weighs with a standard-length barrel and standard stock, and weighs with a shorter barrel and collapsible stock. The short barrel is shorter than a standard M240 barrel, and with the collapsible stock the M240L can be made shorter. The smaller and lighter variant of the M240L is the
M240P. The M240P is not used as often as its predecessors. The Army initially bought 4,500 M240Ls, and plans to buy 12,000 total. Although Barrett did not participate in the solicitation program, the company felt that it could produce an equivalent weight reduction by more efficient manufacturing methods instead of simply switching to the much more expensive titanium receiver. In addition, the company makes the point that the majority of worldwide titanium reserves are coming from
Russia and
China. Should relations between the United States and these countries sour, it would become much harder to find sources of titanium. Thus Barrett designed the 240LW and 240LWS, keeping the standard M240 technical data package, while more efficiently manufacturing the receiver.
Barrett 240LW The Barrett 240LW (Light Weight) is a general-purpose machine gun capable of mounting on a bipod, tripod, aircraft, or vehicle. It is belt fed, air-cooled, gas operated, fully automatic and fires from an open bolt. It features an adjustable buttstock with a hydraulic buffer, feed pawls, a fluted quick detach barrel, a new handguard with Keymod attachments, a new quick detach titanium bipod, adjustable carrying handle, a rivetless receiver, and a three position gas regulator.
Barrett 240LWS The Barrett 240LWS (Light Weight Short) gas operated, belt fed, open bolt, medium machine gun is a shortened variant of the 240LW. The design concept of this variant is to produce a viable medium machine gun that would serve in a special operations capacity, where a small team of operators could maximize a medium machine gun by having it in a shorter and lighter package than its big brother, the 240LW, or the equivalent M240B. This follows in the footsteps of the
Mk 48 and the
M60E6 medium machine guns, also designed for the small unit role. The Mk 48 is a variant of the
M249 light machine gun, scaled up to chamber 7.62×51mm NATO; it has come across some issues in its service life; it was never designed to be a general-purpose machine gun, while the M60E6 arguably came too late to make a difference in USMC and US Army general machine gun adoption, being that the M240 design was already well standardized within the Department of Defense ranks. Both offerings are more focused on Special Operations in US Service. However, the primary intended use of the LWS is not to be mounted, but instead to be part of a small team that needs additional firepower while on a foot patrol.
OOW240P The OO240P (Patrol) is similar to the GPMG variant but with a shorter barrel. The shorter barrel features dimpling which reduces weight while increasing heat dissipation with no loss of strength or durability. The barrels are available with either single or three position gas regulators and are fully compatible with existing blank fire adaptors.
M240-SLR The M240-SLR (Self-Loading Rifle) is a semi-automatic only configuration of the M240, and fires from a closed-bolt.
Daycraft Systems The FMG 7.62 is similar to the M240 but with a one-piece instead of riveted steel receiver, which reduces its weight to 17.8lbs (8kg). ==Users==