Marine: A Guided Tour of a Marine Expeditionary Unit tcml-4

by Tom Clancy

  An M249 Squad Automatic Weapon (SAW). The SAW is a 5.56mm fully automatic machine gun, and one is assigned to each four-man Marine fire team.

  JOHN D. GRESHAM

  In 1957 the BAR was replaced by the M60, a close copy of the World War II German MG42 light machine gun. The Army "improved" that design, which led to frequent stoppages and jams, poor durability, and barrels prone to overheating. It fired 7.62mm ammunition instead of the 5.56mm/.223-in. round used by the M16. Thus, a platoon with both weapons had to manage two separate ammunition supplies, complicating logistics. Also, the M60 was still very heavy (at 18.75 lb/8.5 kg) to be lugging around with 10 to 20 1b/4.5 to 9 kg of ammunition. Thus, M60 gunners dreamed of a lighter weapon which would be easier to carry and operate, use the same 5.56mm/.223-in. ammunition as the M 16, and carry more rounds for the weight.

  By the late 1970s, the Army and Marines agreed to procure a non-developmental (i.e., "off-the-shelf") replacement for the M60 in rifle squads. After many models were evaluated, the winner was a weapon from Fabrique Nationale (FN) of Belgium. This became the M249 Squad Automatic Weapon (SAW), first issued to Army and Marine units in the mid-1980s. Since then a "Product Improvement Program" kit has modified the barrel, grips, stock, buffer, and sights. The M249 is an attractive little weapon, not much larger than an M16A2. With a folding bipod and tool kit, it weighs only 15.2 lb/6.9 kg and is some 40.9 in./103.8 cm long. A sling allows the gunner to fire it from over the shoulder when on the move. It can accept either the thirty-round 5.56mm/.223-in. magazines of the M 16A2, or a two-hundred-round belt (which is preferred). The belted ammunition comes in a plastic box, which weighs only 6.9 lb/3.1 kg. This is a vast improvement over the M60, in terms of the weight a fire team has to lug around the battlefield. Marines issue one M249 to each four-man fire team. The other three team members have M16A2s, and one of these comes with a M203 40mm grenade launcher, so that each fire team has a machine gun, three combat rifles, and a grenade launcher. Quite a lot of firepower for just four men.

  For my demonstration, Colonel Nance's instructors had flipped down the folding bipod legs at the front of the M249 so that I could fire from a prone position. This is the most comfortable and accurate way to fire the M249, because it tends to spread the recoil over three points (the two bipod legs and your shoulder), limiting the movement of the weapon. As I mentioned earlier, you can load the weapon either from the bottom with a 30-round M16 magazine or a 200-round belt which feeds across the top of the SAW. To load, you attach a plastic belt box to the left side of the SAW. This done, you raise the receiver cover and pull the belt over and across the receiver feed tray, align the first round over the feed tray, and close the cover. Then you pull back the cocking handle to load the first round, release the safety, and pull the trigger.

  The SAW fires at a satisfying 725 rounds a minute. While you are putting a lot of rounds onto the target, the weapon is not cycling so quickly that you cannot control it. You can fire single shots or short bursts easily, or empty a whole box of two hundred rounds in just over 16.5 seconds. Accuracy of the M249 is quite good. The sights are more complex than those on the M 16A2 (with adjustment knobs for elevation and windage), but when properly adjusted, they help you to consistently put rounds on target out to an effective range of about 1,000 meters/3,281 feet. I was able to put a stream of bullets right into the chest of a man-sized target at 200 yards/183 meters without difficulty. When you fire the M249, there is a solid feel with very little kick or travel. Firing the SAW is so nice that before long, you begin to feel invulnerable and omnipotent. As an SAW gunner, you have to deny yourself this feeling, because you are no better protected than any other infantryman, just better armed. If the SAW has a vice, it is the one common to all machine guns, a tendency to jam during long bursts. This is one reason why short bursts are encouraged (the obvious desire to conserve ammunition is another reason). The SAW is easily cleared in the event of a jam, simply by lifting the cover plate and pulling the jammed round clear. The M249 SAW is an excellent light machine gun. Its standard M988 5.56mm/.223-in. ammunition means that every Marine in a four-man fire team now fires the same ammunition, simplifying logistics and maximizing the utility of a team's load. I like it!

  M240G Light Machine Gun

  When the Army and Marines replaced the M60 at the squad/fire team level, they also had to replace it in other medium-machine-gun roles. In its final version, the M60E3, it had been used as a pintle-mounted weapon on vehicles and aircraft (M-1 tanks, trucks, helicopters, etc.), as well as in heavy weapons platoons. In these roles, the 5.56mm/.223-in. round really does not have the hitting power and range required, so the M60E3 with its 7.62mm round was retained well past its prime.

  The Army and Marine Corps finally found the ultimate replacement for the M60E3 in the M240G. Gunners like it for its reliability and reduced maintenance requirements. The M240G is basically a scaled-up M249 SAW, firing 7.62mm ammunition. Designed and built by FN of Belgium, the M240G is a lightened version of the original M240. The 240G is functionally identical to the M249 SAW, except for the following features:

  • It is longer (47.5 in./ 120.6 cm) and heavier (24.2 lb/ 11 kg) than the M249, or for that matter, than the M60E3. This is the main "down" side to the M240G.

  • The M240G fires the NATO-Standard 7.62mm ammunition instead of the 5.56mm/.223-in. rounds. This makes for better hitting power and greater effective range (out to 1.1 miles/ 1.8 km).

  • It has three selectable rates of fire, between 650 and 950 round per minute.

  Aside from these differences, the M240G is almost identical to the SAW. Now every medium machine gun in the U.S. military inventory will come from the same basic family. Like its little brother, the M249 SAW, the M240G is popular with the troops, though the Marine recruiters joke that they are looking for bigger recruits to lug it around the battlefield!

  Combat Shotguns

  In really close combat, there is nothing better than a shotgun (except maybe a flamethrower!) for hitting power. Marines use three different though similar commercial shotguns for CQB missions. The Remington 870, Winchester 1200, and Mossberg 590 have all been adapted for combat by adding a bayonet attachment, sling, and a phenolic buttplate to soften the recoil. Shotguns are not carried as a primary weapon (like the M 16A2 or MP-5N), but as special secondary weapons for use at close quarters. In addition to the obvious anti-personnel role, they can also be used to blow open a door (by blasting the lock or demolishing the hinges); and they make a fine "non-lethal" riot-control device. A new family of shotgun shells from MK Ballistic Systems, called Flexible Baton-12, fires projectiles that look like small rubber beanbags. These deliver enough force to knock down a human being, without the blunt trauma often associated with so-called "rubber" bullets.

  Colonel Nance and his staff are now preparing to evaluate a more capable combat shotgun. Though the actual weapon has yet to be selected, it will certainly have a large magazine (thirty rounds or more), and provide a semi-/fully automatic firing capability. When the Marine Corps puts its stamp of approval on this new shotgun, it is likely to be procured by law enforcement agencies all over the world.

  Foreign Weapons

  Quietly and discreetly, Colonel Nance's Weapons Training Battalion introduces new Marines to some of the weapons that they may face or capture on future battlefields. The first reason is obvious: Marines in the field should recognize the sound of an enemy weapon being fired, and know to get down out of the line of fire. Many weapons, like the ubiquitous AK-47 combat rifle, have a highly distinctive sound signature, and knowing this can help you locate its firing position. In addition, knowing an enemy weapon allows you to identify its weaknesses, possibly giving you an edge in combat. Finally, Marines have to be ready to fight with what they can get if they are lost, cut off, or even abandoned (remember Wake Island and Guadalcanal). To this end, new Marines are indoctrinated in the characteristics of weapons used by other nations. Many of the foreign weapons that Marines learn about at Quantico are of cr
ude but effective design like the AK-47. Thus, knowing how to use them will continue to be an important battle skill for Marines.

  Grenades, Mines, Explosives, and Breaching Tools

  While firearms are the primary tools of an infantryman, there are times when a gun will not do. Ordnance engineers like to say that there is no condition in the human experience that cannot be solved by an appropriately shaped, sized, timed, and detonated charge of high explosive. Explosive weapons have had an important place in close combat since the invention of the grenade several hundred years ago. Today's Marines can carry a variety of grenades, mines, and other devices in their rucksacks, and we're going to take a look at them here.

  Hand Grenades

  Shortly after gunpowder reached the West in the Middle Ages, some creative warrior took a handful of the new explosive, packed it into a container, lit a fuse, and threw it at his enemy. This was a good idea when it worked. The problem was that it didn't work all that often. Early grenades were frequently more dangerous to their users than their intended victims. Because of the unreliability of the explosive and fuses, you could never really be sure they were going to go off, or how big an explosion ("lethal blast radius") you would get.

  Modern grenades commonly used by Marines include:

  • M67 Fragmentation Grenade-Weighing 14 oz/.4 kg, it carries an explosive charge of 6.5 oz/ 184.6g of Composition B. When you pull the pin and release the safety handle (called a "spoon"), there is roughly a four-to-five-second delay prior to detonation. When it goes off, it spews fragments out to a lethal distance of around fifteen meters/forty-nine feet. The user must either be under cover when it explodes, or throw it far enough to be safe from the blast.

  • M7A3 CS Riot Hand Grenade-This is a "non-lethal" device, designed to deter or incapacitate a rioting crowd. Weighing only 15.5 oz/.44 kg, it is loaded with a mixture of pelletized CS (tear gas) and a burning agent, which helps atomize and disperse the gas. When inhaled, ingested, or exposed to mucous membranes (eyes, mouth, etc.), it incapacitates the victim within fifteen to thirty seconds, with an effect duration of less than ten minutes following exposure to fresh air and, if necessary, water to flush the eyes and mouth. Troops using the M7A3 normally wear a gas mask to avoid exposure themselves.

  • M18 Colored Smoke Hand Grenade-The M18 is not designed to kill or wound anyone. It simply marks areas for helicopter landing zones and no-shoot areas during strikes by aircraft and helicopters. Weighing some 19 oz/.54 kg, these grenades come in four varieties: red, green, yellow, or violet smoke. Each M 18 will generate smoke for approximately fifty to ninety seconds, and the volume of smoke is suf ficient for screening squad movements, if the wind is not too strong.

  There is little research on improved hand grenades, since these do exactly what is required. The Marines maintain a stock of more than 1,138,000 grenades of all types, showing how important they are to the firepower of the Corps.

  M203 40mm Grenade Launcher

  One of the problems with hand grenades is that a human being (even Dan Marino) can only throw one so far. In World War I grenade-throwing attachments were developed for bolt-action rifles to provide more standoff range for the infantry. These were not direct-fire weapons, and they were not terribly accurate; the grenades had to be lofted, like a mortar round. During the Vietnam War the U.S. Army introduced the M79 grenade launcher (nicknamed the "thump gun"). This stubby weapon, resembling an oversized, sawed-off shotgun, fired a 40mm shell, called a grenade, to a range of about 150 meters/492 feet. At this range, a good thump gunner could put a round through a door or window. Each 40mm projectile has about the same lethality as a hand grenade, but with considerably more accuracy and range. There are several different types (smoke, fragmentation, gas, flechette, etc.), with various effects.

  The M79 was used extensively in Vietnam, and is still favored by law enforcement agencies for riot control and SWAT teams, but it is an extra weapon the soldier has to lug around that is not useful for anything else. Thus, the M203 grenade launcher was created. The M203 is a "clip-on" device, which attaches to the bottom of the forward receiver of an M16A2 combat rifle. A Marine with the M203 still has full use of his M16A2, but he can also launch 40mm grenades. You load it by pushing the barrel of the M203 forward, and then sliding a round into the breech. By pulling the barrel tube backwards, you lock the weapon shut and are ready to fire. All you have to do is release the safety, aim the weapon, and pull the M203's trigger, located just forward of the magazine loading chute of the M16A2. Surprisingly, the M203 is quite accurate, and gunners can put rounds through a door or window at quite a good range. Each fire team includes one M203 gunner. It is a deadly little weapon, well liked by Marines.

  An M203 40mm grenade launcher attached to an M4 5.56mm carbine. The M4 is the shortened version of the M16A2 combat rifle.

  JOHN D. GRESHAM

  Mines

  Mines are weapons that wait, sometimes for decades. Combat soldiers both love and hate land mines. They love to sit behind a minefield and watch the enemy blunder into it. But they hate the feeling of helplessness and terror that comes from being caught in a minefield, seeing their friends suddenly and horribly maimed. And then once the war is over, the winners get to pick all the damned things up and disarm them. Unfortunately, this doesn't always happen, and large areas of luckless countries like Cambodia, Angola, and Afghanistan have been rendered uninhabitable by millions of land mines. Although some European countries that profited hugely from the sale of land mines are beginning to ban their export for humanitarian reasons, mines are so effective and cheap that there is little hope of a workable international law prohibiting their manufacture and use.

  The Marines deploy a variety of different mines, including the following, which are man-portable:

  • M16A1 "Bouncing Betty" — This is a "bounding" anti-personnel mine. When someone steps on one of the firing prongs (which are left exposed when the M16A 1 is buried), a small propelling charge fires it about 6f/1.8m into the air, at which point it detonates. The M16A1 contains a 1-1b/ .45-kg explosive charge, which produces a lethal fragmentation range of around 88f/27m.

  • M18A1 "Claymore" — This is a flat curved plate filled with steel balls embedded in plastic explosive. It has folding metal prongs that stick into the ground and a chilling label embossed on the housing: "This side toward enemy." It functions like a huge shotgun shell. Once the M 18A1 is emplaced, it can either be fired by a trip wire or command-detonated from a distance. When detonated, the 1.5-1b/.68-kg C-4 charge fires a 60deg fan-shaped pattern of fragments, each the size of a ball bearing. The fragments are lethal out to a range of around 328f/100m. The Claymore is primarily used for ambushes, but it can also function as a "silent sentry," covering ground that cannot be brought under direct observation and fire.

  Anti-personnel mines are effective against opposing infantry, and Marines can carry them in sufficient numbers to make them a real threat. Though there are larger mines like the M15 and M18 used against tanks, they are too heavy to be man-portable.

  Explosives and Breaching Tools

  In addition to grenades and mines, Marines frequently carry supplies of plastic explosives and detonation gear for demolitions. They may use explosives to breach doors and other obstacles. In most cases, these are improvised devices, tailored to a particular situation. Today, C-4 is the most common explosive used by U.S. forces. With the consistency of modeling clay, it is extremely powerful, clean, and quick-burning. Another common explosive tool is detonator cord, which burns so hot and fast it can cut through metal. These explosives are usually detonated electrically, with a positive control whenever possible. Explosives experts hate time fuses, because they are just one more thing to fail, or to be disarmed later.

  The growing menace of domestic terrorism raises legitimate concerns about showing people how to build homemade explosive devices. For that reason I will not give you specifics. That said, explosives have some positive uses; they are not always used to kill or injure people
. Consider a door. Any cop will tell you that going though a door with a perpetrator on the other side is a good time to have your insurance policy paid up and your sins confessed. Door-busting quickly and safely is vital, especially in the tricky business of hostage rescue. So consider this little improvised device.

  Cut a large coffee tin or other institutional food container in half, down the long axis. You now have a concave container, into which you loop a length of detonator cord and a detonator. On top of the detonator cord, you pack the remaining space with soft plastic packages of saline solution from the medical supplies carried by your Navy corpsman. Once this is done, the open side is sealed with duct tape. Now apply double-sided sticky foam tape over the duct tape. Then slap the sticky side onto the door you want to go through and step back. When the detonator is fired, it drives the saline liquid forward with such force that the door is knocked off its hinges. Since the explosion is quick and clean, and the area is drenched with the saline solution (its just salt water, remember), there is virtually no danger of fire.

  Marines learn dozens of such tricks for taking down different kinds of structures. To a properly trained Marine, explosives are another tool, like a saw or bulldozer, to get a job done. In the arts of combat, Marines are world-class masters of creative improvisation.