American soldiers in Vietnam had strong opinions about their weapons. Some guns saved lives. Others got men killed. This breakdown covers the most despised firearms used by US forces based on after-action reports, military investigations, and soldier testimonies documented in official records and memoirs.
These weren’t just inconvenient weapons. They were guns that failed when lives depended on them, that soldiers actively tried to avoid carrying, and that caused casualties through mechanical failure rather than enemy action. If you’re a veteran watching this, you already know these guns intimately. For everyone else, pay attention.
This is the side of war that rarely makes it into textbooks or movies. Let’s start with the weapon that earned more hatred than any other in the entire war. The early M-16 didn’t just malfunction, it got soldiers killed in firefights because they couldn’t return fire. When the M-16 first deployed to Vietnam in 1965-1966, it arrived with a reputation as a space-age wonder weapon.
Lightweight, high velocity, easy to shoot. Reality hit hard. The rifles jammed constantly. Soldiers would pull the trigger and nothing would happen. In the middle of firefights, with enemy forces closing in, the problems were systematic. The Army issued the rifles without chrome-plated chambers, despite testing showing they needed chrome plating for Vietnam’s humid conditions.
The powder used in the ammunition was changed from the original specification to save money, creating more fouling and residue. Soldiers weren’t issued cleaning kits initially because the rifle was marketed as self-cleaning. It wasn’t. Congressional investigations in 1967 documented the scale of the disaster.
The I Corps committee heard testimony from Marines who’d found dead Americans still trying to clear jammed M-16s. Some had cleaning rods jammed down their barrels. They died trying to clear malfunctions while under fire. One Marine wrote home to his family. This letter ended up in congressional testimony, describing finding a dead fellow Marine with his rifle disassembled trying to clear a jam when he was killed.
The letter asked his family to contact their congressman because our M-16s are getting us killed. The failure rate was catastrophic. Some units reported 30 to 40% of their rifles jamming during firefights. C.J. Chivers, The Gun, extensively documents these failures, including interviews with soldiers who survived firefights where their weapons failed repeatedly.
Soldiers began requesting old M-14 rifles from supply. They’d carry extra AK-47s taken from dead Viet Cong because they trusted captured enemy weapons more than their issued rifles. That’s how bad the early M-16 was. American soldiers preferred enemy weapons. The fixes came slowly. Chrome-plated chambers, better ammunition, cleaning kits, revised maintenance procedures.
By 1968-1969, the improved M-16A1 had become reliable, but thousands of soldiers served with the defective early models. The weapon’s reputation never fully recovered, even after the problems were fixed. The M-60 was the squad automatic weapon, meant to provide sustained fire support. Soldiers called it the pig, not affectionately.
Weight was the first problem. At 23 lb unloaded plus ammunition belts, the M-60 was a burden. The gunner carried the weapon, the assistant gunner carried spare barrels and extra ammunition. Together, they hauled 50 to 60 lb of machine gun equipment through jungle and rice patties while everyone else carried 40 to 50 lb of kit.
But weight wasn’t why soldiers hated it. The M-60 had serious mechanical issues that made it dangerous to operate. The bipod legs were attached to the barrel. Changing a hot barrel, which had to be done regularly during sustained fire, meant handling hot metal legs while under fire. The asbestos gloves issued for barrel changes was inadequate.
Gunners got burned. The barrel change process took too long in combat conditions. The gas system and other components would fail unpredictably. The weapon required constant maintenance, but was overcomplicated for field conditions. Small parts would break, fall out, or get lost. Without those parts, the weapon was dead weight.
More dangerously, the M-60 could run away, continue firing after the trigger was released. This happened when certain parts wore out. A machine gun firing uncontrollably until the ammunition belt ran out was terrifying for the gunner and everyone nearby. Several friendly fire incidents resulted from runaway M-60s.
The feed system jammed frequently. Ammunition belts would fail to feed properly. Spent brass would sometimes fail to extract, requiring the gunner to clear the jam under fire. For a weapon that was supposed to provide reliable suppressive fire, the M-60’s unreliability was inexcusable. Soldiers’ memoirs consistently mention the M-60’s problems.
Robert Mason’s Chickenhawk describes door gunners dealing with M-60 malfunctions while taking fire. Michael Lee Lanning’s The Only War We Had details infantry frustrations with M-60 failures during firefights. Units that could get M2.50 caliber machine guns for base defense preferred them despite the M2 being even heavier.
The M2 was reliable. The M-60 wasn’t. That tells you everything about how soldiers viewed the pig. The M-79 grenade launcher, called the thumper or blooper, occupies a strange position. Some soldiers loved it, many hated it. The hatred came from tactical limitations that got men killed. The M-79 was a break-action single-shot weapon.
It fired 40 mm grenades with reasonable accuracy out to about 150 m. The problem was single shot. In a firefight, the grenadier could fire once, then had to break open the weapon, extract the spent shell, load a new grenade, close the action, aim, and then fire again. That cycle took precious seconds. During that reload time, the grenadier was essentially defenseless.
The M-79 was his primary weapon. Grenadiers typically only carried a pistol as a backup. In dense jungle where firefights happened at close range, having a single-shot primary weapon was dangerous. The 40 mm grenades had a minimum arming distance of about 15 to 30 m depending on the round type. Closer than that, they wouldn’t detonate.
This created a lethal gap where the grenadier couldn’t effectively use his primary weapon. If enemy forces were inside that minimum distance, which happened constantly in jungle warfare, the grenadier was carrying an expensive expensive club. The tactical doctrine didn’t match the reality of jungle combat.
The M-79 was designed for open terrain engagements where the grenadier could stay back and lob grenades at distant targets. Vietnam’s jungle meant close-range, sudden contact. The M-79 was wrong for that environment. Grenadiers shaded carrying extra weight in 40 mm grenades while knowing their weapon’s limitations. Each grenade weighed about half a pound.
Carrying 20 to 30 rounds meant 10 to 15 lb of ammunition for a weapon that fired once before reloading and couldn’t be used at close range. Later, the M203 grenade launcher that mounted under an M-16 solved these problems. It gave the grenadier a rifle and grenade launcher in one weapon. But soldiers stuck with the M-79 felt vulnerable and underarmed.
Harold Moore’s account of Ia Drang mentions grenadiers’ difficulties in close jungle combat, where their weapon’s limitations became painfully obvious. The M-14 deserves mention, not because it was a bad rifle, it wasn’t, but because it was completely wrong for Vietnam. The M-14 was heavy at 9.2 lb empty. It fired a full-power 7.
62 mm NATO cartridge that created significant recoil. In full auto mode, it was nearly uncontrollable. The muzzle would climb and rounds would go high. The 20-round magazine was quickly emptied in automatic fire. But the real problem was the cartridge itself in jungle warfare. The 7.62 mm NATO round was designed for long-range engagements in European terrain.
Vietnam’s jungle fighting happened at ranges measured in feet, not hundreds of meters. The M-14’s power and range advantages meant nothing when you couldn’t see past 30 ft. The weight and recoil meant soldiers couldn’t carry as much ammunition and couldn’t fire as effectively in rapid engagements.
A soldier with an M-14 and 120 rounds, six magazines, was carrying more weight than a soldier with an M-16 and 300 rounds, 15 magazines. Early in the war, before the M-16 arrived in quantity, soldiers carried M-14s through jungles where the rifle’s length made them awkward, their weight was excessive, and their power was unnecessary. The weapon beat soldiers up physically during long patrols.
Some soldiers appreciated the M14’s reliability compared to early M16’s, but most infantry who humped M14’s through Vietnam’s jungles hated the weight and wished for something lighter and more suitable for close range combat. The M14 was a fine rifle in the wrong war. The M1911 pistol was a legend. Designed in 1911, proven in two world wars.
In Vietnam, soldiers who carried it often hated it. The issues weren’t with the pistol’s design or reliability. The M1911 worked. The problem was that pistols are terrible weapons for combat and many soldiers were issued the 45 as their primary or only firearm. Officers, radio operators, vehicle crew, some helicopter crew, and M79 grenadiers often carried the M1911 as their primary weapon.
In jungle combat where sudden contact at close range was common, having only a pistol was terrifying. The M1911 held seven rounds in the magazine plus one in the chamber. Eight shots. Then a reload under stress. Hitting targets with a pistol under combat conditions is extremely difficult.
Handguns require far more skill and practice than rifles. Most soldiers weren’t expert pistol shooters. The 45 ACP cartridge was powerful but had significant recoil. Follow-up shots were slow. The heavy trigger pull of standard M1911’s made accurate shooting harder. In firefights, soldiers with pistols were massively outgunned by enemies with rifles or submachine guns.
Radio operators particularly hated this situation. They carried heavy radio equipment that prevented them from carrying rifles. Their only weapon was a pistol. If the unit got into heavy contact, the radio operator was one of the most important people present and one of the least capable of defending himself.
The solution many soldiers found was carrying captured weapons. AK-47’s or other enemy weapons gave pistol-armed soldiers a real fighting chance. But officially, they were supposed to rely on the M1911. Many didn’t feel that was adequate. The M2 carbine was the full auto version of the M1 carbine firing the 30 carbine cartridge.
Some remained in inventory and saw limited use in Vietnam. Those who had to use them weren’t happy about it. The 30 carbine round was anemic. It lacked stopping power, particularly through vegetation. In jungle where shots often had to penetrate leaves, branches, and other obstacles before hitting targets, the light 30 carbine bullet would deflect or lose energy.
The weapon itself was lightweight and handy, which was good. But the carbine’s effectiveness was questionable. There were documented cases of enemy soldiers being hit multiple times with 30 carbine rounds and continuing to fight. The 15 or 30 round magazines seemed adequate, but in full auto, the M2 burned through ammunition quickly.
The full auto fire was difficult to control. The weapon’s sights were crude by modern standards. Most soldiers issued M2 carbines were support troops, vehicle crews, or others not expected to be in heavy combat. But Vietnam didn’t have safe rear areas. Bases got attacked. Convoys got ambushed.
Those soldiers with M2 carbines felt underarmed when actual combat started. The M3 submachine gun, called the grease gun, was a World War II holdover still issued to tank crews and some other personnel in Vietnam. It fired 45 ACP from a 30 round magazine. This weapon was crude by design. Stamped metal construction, simple blowback operation.
It was reliable enough and cheap to manufacture. But it was obsolete by Vietnam. The rate of fire was slow for a submachine gun, about 450 rounds per minute. The accuracy was poor beyond close range. The sights were barely adequate. The stock was wire that didn’t provide a stable shooting platform. Most critically, the 45 ACP cartridge from the submachine gun had very limited range and penetration.
In jungle combat, the M3 was only useful at extremely close ranges. Beyond 50 m, it was nearly useless. Tank crews issued the M3 knew they were carrying antiques. If they had to abandon a damaged vehicle and fight as infantry, they’d be doing it with a weapon that was outclassed by nearly everything the enemy carried.
Some crews acquired rifles or other weapons to supplement the M3’s they were officially issued. The M72 LAW was a disposable rocket launcher designed for anti-tank warfare. In Vietnam, where enemy tanks were rare, it got used against bunkers and fortifications. Soldiers had mixed feelings that often leaned towards hatred.
The weapon worked when it worked. The problem was reliability. Duds were common. Pulled a trigger and nothing happens. Or the rocket would fire but failed to detonate on impact. Given that soldiers were often firing LAWs at bunkers that were actively shooting at them, a dud meant immediate danger with no second chance since the LAW was single shot disposable.
The backblast was enormous. Firing from enclosed spaces could injure the operator or nearby troops. The backblast signature also revealed the shooter’s position. Every enemy in the area would know exactly where that LAW was fired from. The training for the weapon was minimal. Many soldiers never fired one until they needed it in combat.
The aiming system was basic. Under stress, accuracy suffered. Missing with your only shot at a bunker that’s shooting at you was a bad situation. The LAW’s effectiveness varied wildly. Sometimes it would demolish a bunker. Other times it would hit and fail to detonate or detonate but fail to neutralize the target. This inconsistency made soldiers distrust the weapon.
The weight and bulk of carrying LAWs on patrol was another complaint. Each LAW weighed about 5 lb and was awkward to carry. But you might need one, so units would carry several, adding weight to already overloaded soldiers. The weapons American soldiers hated most in Vietnam shared common problems. Unreliability when lives depended on them, tactical limitations that endangered users, or being fundamentally wrong for the type of warfare they faced.
The early M16’s jamming problems killed soldiers who couldn’t return fire. The M60’s mechanical issues made it unreliable exactly when reliable fire support was critical. The M79 single shot limitation left grenadiers vulnerable. The M14 was too heavy for jungle warfare. The M1911 pistol was inadequate as a primary weapon.
The M2 carbine and the M3 grease gun were obsolete. The M72 LAW was unreliable. These weren’t minor inconveniences. These were life or death equipment failures. Soldiers documented these problems in letters home, in official complaints, in congressional testimony, and later in memoirs. The weapons that failed earned lasting hatred from those who had to carry them into combat.
Understanding these weapon failures is part of understanding the Vietnam experience. Equipment shortcomings added another layer of stress and danger to an already deadly environment. Subscribe for more reality-based content about Vietnam. Check the description for sources. Everything here is documented in military records, congressional investigations, and veteran accounts.
