Practical Guide to the Operational Use of the MAG58/M240 Machine Gun

Section 1

Operator Manual Introduction

The objective of this manual is to allow the reader to be able to use the MAG58/M240 and tripod mount system competently. The manual will give the reader background/specifications of the weapon; instruct on its operation, disassembly and assembly, demonstrate correct usage of tripod; detail proper firing procedure; and identify malfunction/misfire procedures. Operator-level maintenance will also be detailed to allow the reader to understand fully and become competent in the use and maintenance of the MAG58/M240 general-purpose machine gun.

Figure 1-1 Canadian troops carrying FN MAG in Afghanistan

Description

General Weapon Specifications

• Mode: Full-automatic only

• Operation: Gas

• Cartridge: 7.62x51mm NATO (.308 Winchester)

• Weight (without tripod or ammunition): 26 lbs./12.3 kg

• Overall length: 49 inches/124.5 cm

• Rate of fire: 650-950 rpm

• Range

• Maximum - 3,725 metersCombat Maximum effective - 1,100 meters

• Grazing fire - 600 meters

• Maximum effective range of the M240B for an area target:

Tripod – 1,100 meters

Bipod – 800 meters

• Maximum effective range for a point target:

Tripod – 800 meters

Bipod – 600 meters

Feed

• Ammunition capacity: 50-round soft nylon box, 100-round cardboard box

• Disintegrating metal link - M13

• Direction: Left to right

Barrel

• Length: 24.7 inches/62.7 cm

• Quick changeable-type mechanism

• Muzzle velocity: 2,800 fps/853 m/s

Rates of Fire with the MAG58/M240

• Sustained rate of fire is 100 rounds per minute in bursts of 6 to 9 rounds in 4- to 5- second intervals. It is recommended to change the barrel if firing the sustained rate every 10 minutes.

• Rapid rate of fire is 200 rounds per minute in bursts of 6 to 9 rounds in 2-to 3- second intervals. It is recommended that the barrel be changed every two minutes if firing at the rapid rate.

• Cyclic rate of fire is the maximum amount of ammunition which can be expended in one minute. It is recommended that the barrel be changed every one minute interval if firing at the cyclic rate.

Action

• Locking feature is a rotary bolt.

• Full automatic from the open bolt

• The trigger type is a spur.

• Safety type is a cross bar-push selector with safe and fire settings.

• Safety location is on the left side above the trigger guard.

Background

Figure 1-2 M240B Machine Gun used by U.S. Troops in Afghanistan

The FN MAG is a gas-operated, belt-fed, air-cooled automatic weapon. It uses the long piston-stroke gas system with the gas regulator located below the barrel. The bolt is locked using a swinging shoulder that engages the cut in the floor of the receiver. The air-cooled barrel is quick-detachable, with the attached carrying handle to help handling of the hot barrel. The receiver is made from steel stampings.

The FN MAG is a machine gun manufactured by Fabrique Nationale (FN) in Belgium. It was developed in the 1950s, has been in production since 1958, and has become a widely adopted 7.62x51mm NATO-firing machine gun used by more than 20 countries. MAG stands for Mitrailleuse d'Appui General, translated as general purpose machine gun (GPMG). It has been adopted by more than 80 countries worldwide and is license-produced in the U.S., U.K., Argentina, Taiwan, India, Singapore, and Egypt.

The FN MAG derivative M240 manufactured by Fabrique Nationale's subsidiary FN Manufacturing, Inc., in Columbia, SC, was chosen by the U.S. military for different roles after large world-wide searches and competitions. It has mainly replaced the M60 in most roles, though it replaced some other machine guns in the co-axial. The MAG58 and variants are in production in Belgium and are currently exported to many nations. The MAG58 and its descendants will continue to see service throughout the world for some time.

The M240 is a belt-fed, gas-operated, air-cooled, crew-served, fixed-headspace weapon. It is compatible only with the M13 Link system, also used by many other western (especially NATO) machine-gun designs. Its functionality is demonstrated by its ability to be mounted on the M122A1 tripod, a bipod, on vehicles, or on aircraft.

It was first adopted in 1977 by the U.S. Army as a co-axial tank gun and slowly adopted for more applications in 1980s and 1990s. The M240 and M240E1 were adopted for use on vehicles, which led to further adoption more uses, especially for the U.S. Army and U.S. Marine infantry. While possessing many of the same basic characteristics as its predecessor, the durability of the M240 system results in superior reliability when compared to the M60. The M240 actually has a more complex gas system than the M60, but can function better with lower maintenance and higher reliability, though these features come at greater cost and weight.

Chambered for the 7.62x51mm NATO cartridge, the MAG uses a locking system similar to that of the Browning Automatic Rifle and has made use of some other work by John Browning, who had worked on other earlier designs in Belgium. The downward locking bolt drives the belt-feed system, which is a similar type to that of the MG42, itself borrowing it from an earlier design. They are, however, not identical; the MAG works with the