The HORRORS of the Claymore Mine in Vietnam 

The HORRORS of the Claymore Mine in Vietnam 

On March 28th, 1971, soldiers of the 23rd Infantry Division were asleep inside Fire Base Mary Ann when 50 North Vietnamese sappers slipped through the wire. The base had 43 Claymore mines protecting its perimeter. Every single one had been neutralized. By dawn, 33 Americans were dead and 83 wounded. The very weapon designed to protect them had been turned into a death sentence.

But how did a 3 and 1/2-lb curved box of plastic explosive become the most feared weapon of the Vietnam War? The Claymore story begins not in America, but in the laboratories of World War II. Hungarian and German scientists discovered something terrifying. When you detonate an explosive against a metal plate, the blast doesn’t just go everywhere.

It focuses forward like a shotgun aimed at a wall. They called it the Misnay-Schardin effect and it would change warfare forever. During the Korean War, Canadian forces experimented with a prototype called the Phoenix mine. It worked, but it was crude and unreliable. The Americans took notice. In 1952, a weapons designer named Norman MacLeod at Calord Corporation in Pasadena began developing what would become the Claymore.

His design used ball bearings packed into a curved fiberglass case facing a layer of C3 explosive. But, the early versions had problems. The original M18 used steel cubes instead of balls. They tumbled in flight, losing accuracy and lethality. The solution came from engineers Guy Throner and Bill Kincheloe at Aerojet General, who replaced the cubes with spherical steel balls measuring exactly 1/8 of an inch.

 In 1960, the military type classified the improved design as the M18A1. It weighed 3.5 lb, measured 8.5 in wide, and packed 700 steel balls in front of 1.5 lb of C4 explosive. When detonated, those 700 balls would spray outward in a 60° arc at 3,900 ft per second. Anything within 50 m was in the kill zone. But, perhaps the most famous feature was the simplest.

 Stamped right into the olive drab plastic in raised letters, “Front toward enemy.” It wasn’t just painted on. It was molded into the casing, so soldiers could feel it in complete darkness. Because in war, the smallest mistake gets people killed. The M18A1. Claymore entered combat in Vietnam during the spring and summer of 1966. Within months, it became standard equipment for virtually every American unit in country.

Special Forces teams carried them on reconnaissance missions. Navy SEALs used them in the Mekong Delta. Long Range Reconnaissance Patrols, the LRRPs, carried two per man as standard loadout. And the infantry divisions dug them into their perimeters every single night. The demand was staggering. At its peak, American factories were producing 80,000 Claymores every month.

By the end of US involvement in Vietnam, over 7.8 million had been manufactured. Each mine came packaged in what soldiers called the M7 bandolier, a canvas bag containing the Claymore itself, the M57 firing device known as the clacker, 100 ft of electrical wire, a blasting cap, and a test kit. Everything a soldier needed to turn a trail into a killing ground.

 The army published field manual 23-23 specifically for Claymore employment. It detailed everything from proper placement to firing procedures, and every infantryman was expected to know it by heart. But the Claymore wasn’t just a weapon. It became a psychological security blanket. One veteran from the 25th Infantry Division described it this way.

Two nights out of three, we were on ambush. The Claymore in front of you was the only thing between you and whatever was coming down that trail. And for 3 years, American soldiers bet their lives on it every single night. The first major test came at Ia Drang. In November 1965, the 1st Battalion, 8th Cavalry walked into an ambush by the 66th NVA Regiment.

Outnumbered and surrounded, American soldiers used Claymores to break the enemy assault and create kill zones that stopped human wave attacks cold. But it was at Khe San where the Claymore truly proved its worth. The 26th Marine Regiment was surrounded by 20,000 North Vietnamese regulars. They ringed their perimeter with hundreds of Claymores layered with trip flares, concertina wire, and M14 anti-personnel mines.

When the NVA attacked on the night of February 29th, 1968, Marines fired their Claymores from inside bunkers, sending walls of steel into the assault waves. The perimeter held. The most lethal Claymore operators were the men of MACV-SOG, Military Assistance Command, Vietnam Studies and Observations Group.

 These small reconnaissance teams operated deep behind enemy lines, and the Claymore was their primary weapon. On November 28th, 1968, Spike Team Idaho was compromised by an NVA company. Team leader Sergeant First Class Robert Howard initiated the contact by detonating a Claymore directly into the enemy point element, then led his team through a fighting withdrawal that killed dozens of NVA soldiers.

 Howard would later receive the Medal of Honor. Another SOG team, Recon Team Colorado, was surrounded by 300 NVA. Using pre-positioned Claymores and break contact drills, the eight-man team extracted after inflicting massive casualties. Army Rangers developed a technique called the Claymore break contact. When ambushed, the rear man would fire his Claymore at the pursuing enemy, then sprint past his team while the next man prepared to do the same.

Ranger Team Grasshopper used this technique during a 10-hour firefight, leapfrogging Claymores through the jungle until extraction helicopters could reach them. The statistics tell the story. MACV-SOG teams achieved a documented kill ratio of 158 to 1 against North Vietnamese forces. The Claymore wasn’t just effective, it was the deadliest close-quarters weapon of the war.

But the North Vietnamese and Viet Cong were not passive targets. They studied American tactics obsessively and they learned. The NVA trained specialized sapper units, men who underwent 3 to 18 months of intense preparation. Their mission, penetrate American perimeters and neutralize the Claymores before the main assault.

In October 1967, the 27th Engineer Battalion documented a terrifying new pattern. VC sappers were crawling into American perimeters at night and physically turning Claymores around. So they face the soldiers they were supposed to protect. The report noted that American soldiers had become afraid to detonate their own Claymores, uncertain whether they would kill the enemy or themselves.

The enemy refined their techniques. At Landing Zone Mike and Fire Base Mary Ann, sappers didn’t just turn the Claymores around. They disconnected the blasting caps entirely. They cut the firing wires. They neutralized trip flares so the main assault force could approach in silence. At Fire Base Mary Ann on March 28th, 1971, every defensive position had been compromised before the first shot was fired. 43 Claymores, zero functional.

 By 1969, military analysts estimated that 90% of the mine and booby trap components being used against American forces were of US origin, either captured or left behind during operations. The Claymore design was so effective that both the Chinese and Soviets copied it. The Chinese Type 66, the Vietnamese DH-10, the Soviet MON-50, all were direct imitations of the M18A1, sometimes manufactured using captured American components.

Mines and booby traps, including Claymores turned against their makers, caused 33% of all US casualties during the war and 28% of all American deaths. Statistics tell one story. I called an alert and the CEO said, “What’s going on?” And I said, “There’s an ambush out on the left, 250 m out.

” And he looked at me and he said, “Lurp reports that there recon reports that there’s nothing out there.” I said, “Well, Rebel and I are never wrong. I’m telling you that there’s an ambush that’s out there on the left.” He said, “Move forward, uh dog man.” I said, “I ain’t going anywhere. There’s an ambush that’s out there and I’m not walking into it.

 And I said, “My dog is trained to find this. I’m not.” And so he said, “I’m giving you a direct order.” And I said, “I don’t care. I don’t want to die because you’re direct order because you don’t know what’s going on.” The men who actually carried Claymores tell another. The weapon America had perfected was now killing Americans.

And there was nothing they could do to stop it. One lieutenant from the 25th Infantry Division, Bravo Company, 227th Infantry, the Wolfhounds, served along the Cambodian border in 1969. Two nights out of three, his platoon ran ambush patrols. [music] And one night, everything almost went wrong. He described the moment this way.

The command to initiate the ambush was mine to make and the signal was to blow my Claymore. The triggering mechanism for that was now in the sweaty palm of my hand. At the possibility of popping this ambush and engaging the enemy with our M-16s, one M-60 machine gun, and the couple of claymore mines we had set up along the trail.

 Sweat poured off of our bodies. As I waited for the small group to enter the kill zone, my RTO was whispering softly, “Pop it, LT. Pop it.” I was literally seconds from setting off my claymore when the person holding the flashlight turned around and illuminated the person behind him. A child. Oh my god. They were all young kids. I still wonder what would have happened if I had set off that claymore.

 The kids would have been literally blown to pieces. This lieutenant made it home. But the weight of that moment, of a finger on a trigger, of a decision made in darkness, stayed with him for life. And he was one of the lucky ones. More than 60 years after its invention, the M-18A1 claymore remains standard equipment in the United States military.

It served in Grenada, Panama, the Gulf War, the Balkans, Afghanistan, and Iraq. In 2022, the United States transferred claymore mines to Ukraine as part of military assistance packages, proving the design’s relevance in modern warfare. Unlike traditional landmines, the claymore is exempt from the 1997 Ottawa Treaty banning anti-personnel mines.

 The distinction, command-detonated weapons require a human decision to fire. Victim-activated mines do not. More than 20 countries now produce their own versions. The American M-18A1, the Chinese Type 66, the Russian MON-50. The design Norman MacLeod sketched in 1952 has become a global standard. Over 7.8 million Claymores have been manufactured.

5.6 million were exported to 38 countries between 1969 and 1992 alone. In the jungles of Vietnam, the Claymore was both shield and sword, protector and killer, depending on which side of it you stood. It saved thousands of American lives. It took thousands more when turned against them. The Claymore didn’t win the Vietnam War.

No single weapon could have, but it changed how men fought and died in that jungle, and its legacy continues on battlefields around the world today. Four words stamped into olive drab plastic. The simplest instruction. The deadliest reminder. Front toward enemy. If this video helped you understand the Vietnam War better, subscribe for more military history every week.