April 9th, 1970. Long Fu District, Bajuan Province. Chief Gunner’s mate Barry Enoch is leading a combined American and Vietnamese seal patrol into the mangrove swamps the locals call the forest of assassins. They’re hunting Vietkong infrastructure leaders. Six armed VC try to slip away. Enoch rushes forward, drops three.
Then the jungle opens up from every direction. B40 rockets, automatic weapons. His radio takes a round and dies. Enoch calls in air strikes, fixed wing and helicopter, as close as 20 m to his own position. Then he leads every man through the gap before the VC can seal it shut. Everyone walks out. Navy cross, one of two silver stars, two bronze stars, and a stack of other decorations across three tours with seal team one.
Years later, he wrote one sentence about the weapon on his chest that night. All of the SEALs that carried the MK23 into combat realized just how much we owe to Mr. Stoner. Not the Navy, not the Pentagon, Mr. Stoner. Because the government wanted nothing to do with what he built. Here’s the part that doesn’t make sense until you hear the rest of the story.
Eugene Stoner designed one weapon that could become seven different weapons. rifle, carbine, automatic rifle, light machine gun, medium machine gun, vehicle, turret gun. A shortbarreled beltfed commando variant that weighed 10 12 lb and could put 1,000 rounds per minute downrange. Same receiver, different parts, no special tools.
The Pentagon built roughly 4,000. Then they crushed most of them in the ’90s. 2400 guns turned to scrap at Naval Surface Warfare Center Crane Division. The survivors sell for over $400,000 at auction. There’s almost nothing left. The Stoner 63 is the most important weapon the American military refused to buy, and the men who carried it, the ones who lived because of it, never forgave them for it.
To understand why this weapon existed, you have to understand the man who was angry enough to build it. Eugene Morrison Stoner, born 1922, Gosport, Indiana. Machinist’s son, no college degree. Served as a Marine Corps ordinance specialist in the Pacific where he first started tearing apart automatic weapons to understand how they worked.
After the war, he joined Armalite as chief engineer and designed the AR-15, the rifle that became the M16. Then Colt bought the rights and Stoner watched what happened next. The army changed the ammunition propellant and skipped chrome lining the chamber. The M16 went to Vietnam and jammed. Soldiers died with cleaning rods shoved down their barrels.

The weapon Stoner designed worked. The weapon the army fielded didn’t. So he left, recruited Robert Fremont and James Sullivan, who’d later designed the Ultimax 100, and joined Cadillac Gage in Costa Mesa, California. His pitch, build an entire squad’s worth of weapons from one receiver. The receiver could be flipped 180°.
Gas system on top. That’s a rifle. Magazine feeds from below. Closed bolt. Flip it. Gas system underneath. Beltfed machine gun. Open bolt. Feed tray on top. He named his first prototype M69W. An ambig reads the same upside down. By February 1963, the Stoner 63 was in production. DARPA bought the first 25 units on March 4th.
Marines were evaluating it at Quantico by September, and Stoner made one design choice that tells you everything about what the M16 disaster taught him. He abandoned his own gas system. The AR-15 used direct impingement. Hot gas blows straight into the bolt carrier. Light, but filthy. Carbon builds inside the receiver with every shot.
That’s what killed M16s in Vietnam. The Stoner 63 used a long stroke gas piston instead. Gas hits a piston up front, drives a rod rearward, cycles the bolt, but the dirty gas never enters the receiver. It vents at the muzzle end. Every weapon Stoner designed after the AR-15 used a piston. He wasn’t making that mistake twice.
Now, here’s where the mythology needs correcting. Everyone tells you the Stoner 63 could become seven weapons. What they don’t tell you is that six of those didn’t matter. The rifle weighed 7.9 lb, a pound and a half heavier than the M16. Same caliber, no real advantage. The automatic rifle config had a top-mounted magazine that poured dirt into the inverted receiver every time you loaded it.
What the Stoner 63 actually was, what nothing else on Earth could do in 1963, was the world’s first beltfed 5.56 mm light machine gun. The M249 SAW wouldn’t exist for another 20 years. And in that role, the numbers were staggering. The M60 weighed 23 lb. The Stoner LMG weighed 11.7 half. The Commando variant seals carried 10 and 1/2.
And because the ammo was 5.56 instead of 7.62, a gunner could carry 6 to 800 linked rounds instead of a fraction of that in heavy belts. Walsh put it this way. If you had six stoners and four M60s in a 14-man SEAL platoon, you’ve got company-sized firepower just with machine guns alone. That got you home. 14 men. Companysized firepower.
Over 6,000 rounds per minute. Between 1965 and 72, only 48 SEALs were killed in Vietnam. The VC put bounties on the men with green faces and couldn’t figure out how a squad that small generated that much violence. But the Stoner 63 wasn’t magic. It was demanding, and it killed one of its own. Seal Team 1’s 1967 command.
History states it plainly. The stoner system malfunctioned frequently, but the problem has been eliminated to a certain extent by the proper indoctrination of personnel on the gas system of the weapon. The SEAL’s own documents admit the weapon broke frequently. The cyclic rate was the worst of it. cold.
The weapon fired around 650 RPM. After several hundred rounds, it climbed to,00 a 70% uncontrolled increase. Link separations, misfires, parts failures. Cadillac Gauge eventually designed a rate regulator in the buttstock to cap it at 800. Before that, sustained fire was a gamble. Then April 29th, 1968, Kinhoa Province, a stoner 63A was leaning against a MarkV landing craft’s gunnel.
A pullout pin between the fire control group and receiver vibrated loose from the boat’s engine. The sear disengaged. Openbolt. The weapon started firing on its own. Seal Walter Pope was killed. A push pin smaller than your little finger. The modularity that made the stoner convertible also made it vulnerable. Cadillac gauge redesigned the pin into a threaded screw.
The dead man’s pin. Too late for Pope. The seals didn’t pretend it was perfect, one explained. On my first tour as point man, I chose the KR-15. After a big firefight, I found that I didn’t like changing magazines, so I decided to go with the Stoner 63. Walsh said it simpler. Once you got used to it and you fell in love with the weapon, you never really carried anything else.
They made it work through discipline, cleaning two to three times a day. Cadillac Gage sent factory technicians to train the teams directly. Seal Team 1’s commander said his detachments actively developed firefight tactics around the weapon. The weapon wasn’t reliable. The SEALs were. There’s a difference. Lieutenant Michael Collins, X-ray platoon commander, Naval Academy graduate, carried a Stoner Commando through the Delta.
He’s one of the most photographed seals of the war. the shortbarreled beltfed hanging off his frame like it was part of him. Collins was killed in action on March 4th, 1971. He was still carrying the stoner. So why didn’t the rest of the military get it? The Army Material Command, same organization the inspector general caught rigging tests against the AR-15, evaluated the Stoner in 63 and 64, unacceptable for service use.
They tested it with ammunition so weak that even the M16 couldn’t cycle with it. The Marines disagreed. Quanico gave it a positive evaluation. The Marine Corps Gazette reported the stoner could deliver bursts more accurate than those from a bar. Sullivan claimed the Marines ordered 300,000 units and were blocked by the Senate Funding Committee, which decided Marines should use what the Army uses.
That hasn’t been verified through congressional records, but Sullivan was in the room. Lima Company, Third Battalion, First Marines, carried stoners into combat in ‘ 67. Their verdict, too complicated for a wide issue, but the basic weapon has acquitted itself well in combat. Too complicated for a wide issue, not it doesn’t work, just that you couldn’t hand it to a drafty who’d been in country a week.
That was probably true, but nobody asked whether special operations should keep it permanently. The crulest part came last. The XM207 upgrade passed every Army test between 69 and 71. The project was cancelled anyway. Nixon announced withdrawal. The Stoner didn’t fail a test. It failed a calendar. Total production across all variants, roughly 4,000 units.

The M16 was produced in the millions. You know those little green plastic armymen? The machine gunner, the one lying prone with the oversized bipod? That figure is holding a Stoner 63A, not an M60, not a Bren gun. The most mass-roduced image of the weapon is a children’s toy. 4,000 real ones were ever made. Eugene Stoner died of brain cancer on April the 24th, 1997, buried at Quantico National Cemetery.
7 years later, Special Operations Command launched the SCAR competition, soliciting exactly what Stoner pitched in ‘ 62, a modular weapon family from a common platform. The FNCAR 1, the Sig MCX pushed further when the Army selected the MCX Spear as the XM7 in 2022, replacing both the M4 and the M249 SAW with one platform.
It realized the exact vision a machinist’s son from Indiana drew up 60 years earlier. The lineage is unbroken. Stoner 63 to the Stoner 86 to the KAC Stoner 96 to the Knights Armament LMG. 9B constant recoil system designed by Jim Sullivan, Stoner’s original collaborator, still refining his partner’s work decades after his death.
Ian McCollum of Forgotten Weapons. The ingenuity required to make all of these different variations work on a single receiver is momentous. And the fact that the resulting gun is heralded as one of the best machine gun designs ever made really cements Stoner’s legacy. He was right about the future. The future just took 40 years to agree.
April 9th, 1970. Barry Enoch walks his patrol out of the forest of assassins. Every man alive. The weapon that made it possible was one that the Pentagon built 4,000 of and then crushed into scrap. Enoch spent the rest of his life telling people what that weapon meant, not what it could theoretically become.
Seven configurations, 15 subasssemblies. The modular dream. What it actually did in the dark, in the mud, when 14 men needed to fight like 140, all of the SEALs that carried the MK23 into combat realized just how much we owe to Mr. Stoner. Every modular rifle of the 21st century carries the DNA of a stamped steel receiver that could be flipped upside down.
The man who designed it died 7 years before the world caught up. 4,000 built, 2400 destroyed. The greatest weapon the American military ever refused to buy.