The HORRORS of the XM148 Grenade Launcher in Vietnam

When people talk about the weapons that failed in Vietnam, they usually mention the early M-16, the jamming, the cleaning kits that arrived too late. The men who died with their rifles broken down in their hands. That story is true, but it isn’t the worst weapon America sent to that war, because there was another one.

A weapon Colt designed in 47 days. A weapon the army shipped 27,000 of before anyone realized what it actually did to the men who carried it. A weapon that fired when nobody pulled the trigger. A weapon that arrived in Vietnam in December and was pulled from combat the following May. I have to warn you that some of what you’re about to hear is hard to stomach.

Not because of what the enemy did with it. Because of what it did to the soldiers carrying it. If you’re still here, let’s start with the man who designed it. Because the story of the XM148 doesn’t begin in a jungle. It begins in a hurry. Carl R. Lewis was Colt’s design project engineer in 1965. The army needed an under-barrel grenade launcher to clip beneath the M-16.

Something to replace the stand-alone M-79, which forced its grenadier to carry a pistol because the launcher itself fired only one round at a time. Lewis got the assignment. According to Colt’s own May 1967 internal newsletter, in only 47 days, Lewis wrote the specifications, designed the launcher, drew all the original prints, and had a working model built. 47 days.

That number is in Colt’s own newsletter. Presented as something to be proud of. The design was complex. The barrel housing slid forward to load. The weapon had to be cocked manually for each shot. The trigger projected back on a long steel wire toward the rifle’s grip, so the grenadier wouldn’t have to take his hand off the M-16.

Six pieces broke down in the field. Barrel, pistol grip, receiver, handguard, quadrant sight, and a handful of small pins and clips that got lost in the mud the first time a grenadier tried to clean it. In March 1965, the Army signed a contract for 30 prototypes. They called it the CGL-4. Testing began at Aberdeen Proving Ground and Fort Benning.

The extractors failed. The aluminum castings cracked. The sights worked loose. Colt was given a list of corrections. They made some. They missed others. In January 1966, before the prototype problems were solved, the US Department of Defense ordered 10,500 of them. They renamed it the XM-148. The first shipment of 1,764 launchers reached South Vietnam in December 1966.

That’s where the real testing began. The XM-148 had a long trigger. Not metaphorically. Literally long. A steel wire extension that ran back from the launcher’s receiver to a position just below the M-16’s trigger guard, so the grenadier could fire the grenade without taking his hand off the rifle. In a clean room, on a range, with a dry uniform and a rested mind, this design made sense.

In a jungle, it did not. The trigger snagged on vines, on rucksack straps, on the harness webbing of the man behind you in a patrol bunched up, on the lip of a foxhole when you dropped into it under fire. And when the trigger snagged, the launcher fired. John Cruel carried the XM148 with the Fourth Battalion, Ninth Infantry Regiment, 25th Infantry Division, the Manchu’s.

He talked about the launcher decades later with a veteran’s breakfast club. The cocking mechanism was hard to squeeze. The sight was hard to use. The whole thing snagged in brush. A 40-mm grenade fired from an under-barrel launcher arms itself at 14 to 28 m from the muzzle. Closer than that, it doesn’t explode.

It doesn’t need to. Half a pound of steel moving fast enough that impact alone breaks bone. But 14 m is not far in a jungle. A man with an XM148 walking point on a narrow trail had a live grenade pointed at the back of the man 12 m in front of him. If the trigger caught on a branch, and the branch was always there, the round armed itself 5 m past his friend’s spine.

This is not what soldiers had been promised when the launcher arrived. The Vietnam climate ate metal, salt, humidity, the constant mud of the monsoon. Weapons in 1967 had to be cleaned every day or they stopped working. The M-16 had already taught the army that lesson the hard way. The XM148 was worse. Six pieces, pins, clips, a sight that worked loose under fire.

A grenadier with the 199th Light Infantry Brigade, the first American unit issued the launcher, would have stripped his weapon in a poncho on the floor of a hooch by red-filtered flashlight with the parts laid out on a piece of cloth so the small clips wouldn’t disappear into the mud. Oh, he’d do this every night.

He’d lose pieces anyway. When pieces went missing, the launcher didn’t work. There was no field expedient fix. The grenadier was now carrying a 3-lb dead weight on the underside of his rifle and a bandolier of 40-mm rounds he could not fire. Many removed the launchers entirely. They reverted to the M79, the very weapon the XM148 had been designed to replace.

The Army had ordered 10,500. They ordered more. By July 1967, Colt had built 27,400 XM148s. The men who had to carry them in combat were leaving them behind. The Army Concept Team in Vietnam, known as ACTIV, evaluated new weapons under combat conditions. They watched the XM148 for the first half of 1967. In May, they filed their report.

The XM148 was unsatisfactory for operational use in Vietnam. Five months after the first shipment arrived, the Army had decided. The official directive ordered the XM148 withdrawn from combat use. The grenadiers who’d been carrying them were told to revert to the M79, the stand-alone launcher whose limitations had created the entire program in the first place.

The directive didn’t actually remove the weapon from the war. By 1967, 27,000 of these things had been built. Many were already in armories scattered across South Vietnam. Special Forces teams kept theirs. The US Air Force Security Forces guarding airbases were issued them officially in 1968. The SEALs were still carrying them on operations into the early 1970s.

The Australian Special Air Service Regiment had bolted XM148s onto their L1A1 SLR rifles. They called the resulting weapon the [ __ ] The launcher had been pulled from front-line use. But, it stayed in the war, and it kept firing. Here is what is hardest to explain. The Viet Cong were not stupid. A grenadier with a malfunctioning launcher is still a grenadier with a launcher.

The XM148 might have failed to fire on the first pull. It might have fired by accident on the second. But, when it did fire, when the round chambered correctly, when the long trigger pulled the striker home, when the 40-mm shell spun out of the barrel, it landed where it was aimed. The launcher had a maximum effective range of 350 m against an area target.

A man with one could put a high explosive shell into a tree line at the far edge of a rice paddy without exposing himself to small arms return fire. So, the enemy did not assume the weapon was broken. They could not afford to. A NVA squad leader who heard the click of an American grenadier’s launcher and stood up, assuming the weapon had failed, was making a calculation that might be wrong.

The trigger might have caught on a vine. The cocking knob might not have seated. The grenadier might be reaching for it now, 2 seconds behind the click, and a 40-mm round might be coming anyway. The Americans knew their launcher was failing. The enemy did not. The XM148 was, in the single narrow sense, a psychological weapon.

Soldiers feared their own gear. The men they were aiming it at had to fear it just as much. That is the only thing it had going for it. The US Air Force kept the XM148 long after the Army gave up on it. Security forces personnel, the airmen guarding bases, weapons depots, and fuel storage were officially trained on the launcher in 1968.

The training program continued in some units until 1989. Some Air Force armories still had XM148s in inventory into the 1990s. The reason was simple. Air Force security was not patrolling jungles. They were standing fixed posts on flat concrete. The trigger that snagged on vines did not snag on flight line tarmac.

The launcher that came apart in mud was kept dry in an armory and carried for an 8-hour shift. The same weapon that had failed in the jungle worked perfectly well in a guard tower at Tan Son Nhut. In summer 1967, while the XM148 was still in the field, the Army opened a new competition. They called it the grenade launcher attachment development program.

The acronym was GLAD. Colt entered an improved version of the XM148 redesigned by Henry Into. They called it the CGL-5. Colt offered to ship 20 of them to the Army for free. The Army turned them down without testing. Colt, who had built every M-16 in Vietnam to that point, had now lost the under-barrel grenade launcher contract.

They would later be brought back as a manufacturer. They would never design one again. The winner was AAI Corporation, a research and development firm. Their submission was a pump-action design that had originally been rejected in 1964 because it could not chamber the M79’s standard 40-mm shell. By 1967, AAI had fixed that problem.

AAI delivered 20 prototypes for engineering tests. The pump-action design outperformed every competitor. Philco-Ford’s pivoting barrel, the multi-shot concepts, even Colt’s improved CGL-5. The Army type classified it as the XM203. AAI was contracted to build 600 for field trial in Vietnam. The first XM203s reached the 1st, 4th, and 25th Infantry Divisions, the 101st Airborne, and the 11th Armored Cavalry.

The trial lasted 3 months. A CTIV’s report on the XM203 used a different phrase than the one they’d used on the XM148. The XM203 was suitable for use by US Army units in Vietnam. In August 1969, the X was dropped. It became the M203. Four pieces in field disassembly instead of six. No loose pins. No external cocking handle. No long trigger snake.

A simple trigger group. A pump-action slide. A sight that did not work loose. By 1971, Colt had won the production contract. The same Colt whose XM148 had been pulled from combat 4 years earlier, and was building M203s by the tens of thousands. The M203 stayed in service for 50 years. It only began being phased out for the M320 in the 2000s.

Every American grenadier of every war from Vietnam to Iraq carried one. The XM 148 was a failure. But it was not a useless failure. It proved the concept. An under-barrel grenade launcher could be built. A grenadier could carry both rifle and launcher on the same weapon, freeing him from the M79’s dedicated role.

The weight could be borne. The training could be done. What the XM148 failed to do was survive contact with the place it was used. Its trigger was wrong. Its disassembly was wrong. Its safety was wrong. Its tolerances were wrong. But the idea was right. The M203 took that idea and stripped it down. Every part of the XM148 that had failed in Vietnam, the [clears throat] long trigger, the six-piece teardown, the loose sight, the snag-prone profile, was reversed in the M203’s design.

The new weapon worked because the old one had taught the Army, in real American blood, exactly what not to do. 27,400 XM148s, 16 months in combat, an unknown number of men killed by accidental discharges that were never separately counted in casualty reports because the cause of death was recorded as fragmentation wound, the same as any other.

And out of all of that, the M203, the launcher that worked, the launcher that gave every American infantry squad organic indirect fire for 50 years. The Air Force kept training airmen on the XM148 until 1989. The last security forces armory to retire one did so in the early 1990s, Carl R. Lewis, the engineer who designed it in 47 days, won a national materials award from Colt’s internal newsletter in May 1967.

The same month ACTV recommended his weapon be pulled from combat. The award and the withdrawal arrived in the same month, in the same year. From the same company. Nobody at Colt seemed to notice the contradiction.

Disclaimer : This content may be created by AI for entertainment purposes. Any resemblance to real persons, events, or places is coincidental.