By Kevin Dockery
A new weapons system became available to the SEALs soon after their direct involvement in Vietnam began. And this new weapon became something of a trademark of the Teams during the late 60s and early 1970s.
There is no other weapon so closely connected with the Navy SEALs of the Vietnam era than the Stoner light machine gun. For the operators in the Teams, the weapon was either lauded or vilified, loved or hated, with very little middle ground.
In spite of appearances, the Stoner 63 system and its variants were not first taken into combat by the men of the Navy SEALs. Instead, the U.S. Marine Corps had combat tested the Stoner as early as 1966. The USMC tested the Stoner, had it modified, liked it, and were promptly told they couldn’t have them.
As has been mentioned, the Stoner 63 was unique in the field of military weapons. A single receiver could be used to assemble any of a variety of weapons, from short carbine to a fixed machine gun. When set up as a carbine or rifle, the gas system of the Stoner is above the barrel and the weapon fires from closed-bolt. Set up as a belt or magazine fed machine gun, the gas system of the Stoner can be seen below the barrel and the weapon fires from open bolt. This arrangement allows the Stoner to fire most accurately (closed bolt) as a shoulder weapon while the open-bolt system allows air to circulate better and prevents cook-offs in a support-fire automatic weapon.
Early in 1967, the SEALs first became interested in the Stoner 63, primarily as a belt fed light machine gun. The SEALs were entering a new stage in their direct actions in Vietnam. SEAL Team Two was just starting to deploy platoons for combat in Vietnam at the end of January, 1967. Maximum firepower in a minimum package was a prime concern to the SEALs. On January 17, 1967, the US Navy Test Station ordered eight Stoner 63 light machine guns for testing in combat by the SEALs.
Within a month of the new Stoners being received by the Navy, they were sent out to the SEALs in Vietnam. The limited number of weapons available resulted in only one Stoner being shipped to each deployed platoon. Though the Stoner was known for requiring regular maintenance for consistent functioning, the weapon was well received by the SEALs.
SEAL TEAM ONE – COMMAND AND CONTROL HISTORY – 1967
(b) PERFORMANCE OF WEAPON SYSTEMS
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 Stoner system performs well when properly cared for and is the most effective automatic weapon for SEAL Team operations. The weapon itself is sufficiently light that the automatic weapons-man can carry a realistic combat load of ammunition and still move with relative ease.
There were a number of difficulties with the new weapon being fielded in the Teams. But in general the Stoner fit the need for a light weapon with high firepower nicely. One of the more unusual problems the operators had with the Stoner was a certain lack of ammunition. Though the Stoner fired the same .223 round the SEALs had in abundance for their M16’s, the Stoners required linked ammunition. Though a limited supply of pre-linked ammunition was supplied, packed in 150-round plastic ammunition boxes that could be hung on the Stoner, the majority of the Stoner’s ammunition had to be supplied locally.
The special S-63 link for the Stoner came packaged in a small cardboard drum that held thousands of links. The link was very much a reduced-size version of the M13 link used with the M60 machine gun but was unique to the Stoner weapons system. There were more problems with the Stoner 63 for the SEALs than just policing used links and loading belts. It was very much a case of one service not talking to the other that resulted in the SEALs having many of the same problems with their Stoners as did the Marine Corps when they tested the system.
In spite of the minor difficulties run in to while fielding the new weapon, the Stoner soon earned itself a solid position in the SEALs armory. The Stoner needed more cleaning and closer attention to detail in its maintenance than other weapons did, and there were still bugs that had to be worked out of the system.
The SEALs liked the Stoner, but the weapon still needed a good deal of improvement before being fielded in quantity. When the second Platoon of SEAL Team Two returned from Vietnam after their first deployment, a series of recommendations were listed by the Platoon officers and men. Included in these recommendations was a very specific one directed to the Stoner;
Excerpt from SEAL Team Two, 2nd Platoon’s Vietnam operations, 30 January to 30 May 1967
Weapons and Equipment
8. Use of the Stoner LMG is not recommended until the drum magazine becomes available.
The plastic box used to attach a supply of ammunition was considered just too difficult to use in its available form. Hanging as it did one the side of the LMG, when the box was knocked off by an operator’s knee, the ammunition belt would just trail out of the box into the mud. This was only one of several recommendations taken into account by the Navy when they ordered additional Stoners for the SEAL Teams. On 25 May, 1967, Cadillac Gage received a phone call from the Naval Ordnance Test Station requesting a delivery date for 36 additional Stoners. All of these weapons were to be 63As in the light machine gun configuration and equipped with the 150 round drum magazines.
The Stoner machine gun had become a stock item in the SEAL armory by the middle of 1967. Several hours were dedicated to the weapon, its use, and its maintenance during pre-deployment training for Vietnam. Each deploying SEAL platoon now had at least two Stoners, one for each squad, with more desired. SEALs who demonstrated a penchant for the weapon were usually allowed to carry one. These SEALs were often referred to as Stonermen in later recounting of particular actions. For the weapon itself, SEAL Team One was the primary unit for developmental items and the Stoner was secure on their list for attention;
SEAL TEAM ONE – COMMAND AND CONTROL HISTORIES
1967, Enclosure 3, (j) Research and Development, pg 13-14
.. A listing of special procurement actions completed is summarized below:
(#22) Stoner 63A
(#28) Stoner Drum Magazine
(#29) .223 Linking Machine for Stoner Ammunition
The new drum for the stoner made the weapon considerably more dependable while moving. An ammunition belt was secured in the drum and held underneath the receiver, close to center of balance of the weapon. Early experiments by Cadillac Gage in 1966 had resulted in a small 100 round drum, but this device was quickly dropped as impractical. The first model drums were made of spun aluminum and had a double-pinned bracket that secured them to the bottom of the receiver at the back of the forestock and front of the trigger group.
The double-pinned drums were secure, but very difficult to reload without taking them completely off the weapon. The second model drum was secured by a pin to the rear of the forestock where it was free to pivot. The rear portion of the drum mount had a lug that fit under the magazine catch on the front of the trigger group. This model drum could be unlatched and swung down for reloading without having to completely dismount the drum from the weapon.
The drum was mechanically very simple, not much more than a round container with a removable back. A 150 round belt would be coiled together in a counter-clockwise spiral and inserted into the back of the drum with the bullets forward. The loose end of the belt would be slipped up the guide located on the left side of the drum. The back of the drum would then be secured in place with its twist-latch and the ammunition supply for the Stoner would be ready for use.
A stamped-metal cover was hinged at the outside, top of the feed guide on the left side of the drum. This cover could be folded back, exposing a short length of the belt. A somewhat fragile spring clip was on the side of the drum’s feedway to help keep the loose belt from slipping back into the drum.
Individual SEALs developed their own manner of carrying ammunition for their Stoners. Since the drums were relatively slow to reload during a patrol, the loaded drum would be kept secured for use while moving on patrol. When set up for an ambush, another method would be used to feed the Stoner.
SEALs would often carry their extra supply of ammunition belts slung across their shoulders and crossing the chests and back like bandoleers. Sometimes, an extra t-shirt was worn over the belts, keeping them out of the worst of the dirt and mud and preventing them from shining. On getting into a fixed position, such as an ambush site, the belt in the drum of the Stoner would be taken out of the feed tray and left hanging from the drum.
A loose belt of ammunition from the SEALs “bandoleers” would be piled next to the weapon, possibly on a piece of cloth or gear to keep it out of the mud, and loaded into the weapon. In case the SEAL with the Stoner had to break cover and move out, it was a simple matter to snap the end of the drum’s belt onto whatever belt was left in the feed tray.
Unlatching the magazine release allowed the empty drum to swing down until the back cover was free of the weapon. Turning the cover latch would remove the whole back of the drum. To reload the drum in the field, a SEAL could reach to his bandoleers of belts and break the link connection between any two rounds.
Keeping the loops of belts in 150 round or shorter lengths made the next step in reloading a drum relatively easy. The SEAL would pull out his loose belt of ammunition, wrap it clockwise around his finger, and slip it into the back of the drum. feeding the end of the belt up the feed chute, securing the cover, and snapping the drum back into place underneath the weapon allowed the fresh belt to be loaded into the receiver.
Other SEALs made additional modifications to their weapons to fit them to the individual’s taste. No changes were allowed that could jeopardize the dependability of the weapon, otherwise it was up to the individual SEAL. When the Stoner 63A’s arrived at the two SEAL Teams, they were accompanied by a number of complete systems for the weapons. Though the primary configuration of the Stoner used by the SEALs was as the belt fed light machine gun. At least two SEALs used other configurations.
These SEALs found the carbine configuration of the Stoner to their liking. The only magazines supplied with the Stoner systems held a full 30 rounds of ammunition. This larger magazine capacity was considered a big plus by the SEALs who knew about it. The standard M16 magazine at that time (1967) held 20 rounds. The larger 30 round M16 magazines were available, but were very scarce in the SEAL Teams in 1967 and 1968. The short, handy, Stoner 63A carbine, with it’s folding stock and 30 round magazine was the only other configuration of the Stoner system to see any use by the SEAL Team in Vietnam.
One reason that the Stoner system didn’t see wider use with the SEALs in the carbine or rifle configurations was the limited number of 63A receivers that had been purchased by the Navy. Eventually, all of the available weapons were set up as belt fed light machine guns. But some of the conversion parts were still put to use by the SEALs. At least one Stonerman attached the vinyl-covered tubular steel (referred to as the wire type) folding stock of the carbine configuration to his Stoner machine gun. This made for a very compact package of firepower, even though the folding stock wouldn’t secure properly to the side of the weapon.
In spite of the good reception the Stoner received from the SEALs, there were still a number of problems with the design that had to be worked out. Most of these details developed from the SEALs experience with the weapons. The SEALs also gave their Stoners a lot of hard usage so even with the careful maintenance they received, weaknesses showed up faster with the Teams than they would have with other units.
SEAL TEAM TWO – COMMAND AND CONTROL HISTORIES
1968, Enclosure 1, Special Topics, pg 9
The Stoner LMG has been modified due to suggestions submitted from members of SEAL Team TWO who have used the weapon in combat.
Cadillac Gage was very responsive to the SEAL requirements for modifications to the Stoner 63A. Feedback from the field resulted in a number of minor changes to the weapon. The only difficulty with the company response to the input from the Teams was the gradual changes in the parts to the Stoner system. It soon became hard for anyone not very familiar with the differences between the Stoner 63 and the 63A and the Team’s requested modifications to the 63A to make sure the correct parts went into the correct model guns.
But during the Vietnam era, such problems of commonality of parts were not a difficulty for the SEALs. Operators who preferred the Stoner made sure that their weapons operated correctly, and this testing was conducted constantly during predeployment training. This made sure that any problems were corrected long before any specific Stoner went into combat.
One problem with the Stoner centered on the basic design of the weapon and took a major change to correct it. The ejection port on the Stoner was on the left side of the weapon when set up in the light machine gun configuration. Feeding from either the plastic box hanging from the feed tray or the 150 round drum caused a jam known as “spin-back”.
Sometimes when firing, an ejected cartridge case would strike the box, or more often the drum, and bounce back into the receiver. The empty case would block the bolt going forward and stop the weapon from firing until it was cleared. This problem did not happen constantly, only about one or two percent of the time when the weapon was fired. This spin back problem was serious enough to require correcting.
Moving the ejection port of the Stoner was out of the question as that would require a major change in the receiver and a number of internal parts. Instead, the direction of feeding was changed from the left side of the weapon to the right. The right hand feed involved replacing the feed cover and feed tray but eliminated being able to use the drum magazine. SEALs who found that their individual Stoner either didn’t have spin-back problems, or liked the drum enough to accept the occasional jam, stayed with the left-hand feed. Others used the new right hand feed mechanism and a new method of feeding a belt.
SEAL TEAM ONE – COMMAND AND CONTROL HISTORIES
1969, Enclosure (2) (c) 6, Research and Development
2. SEAL Team ONE is in the process of being supplied with a new type of feed system for the Stoner Weapon, that practically eliminates the danger of shell spinback which was one of the major causes of malfunctions.
c. LINKING MACHINE FOR 5.56MM BALL AMMUNITION – Provides a portable linking machine for 5.56 MM Ball ammunition as used by the Stoner 63A weapon system. One unit is now in SEAL Team [ONE].
Along with the right hand feed mechanism was a new method of loading the Stoner 63A with the 100 round plastic boxes. The hanger was a device that fit underneath the center line of the receiver, in the same position the belt drum was in. A plastic ammunition box could be slipped into the hanger where it would be held securely and the belt fed into the weapon. The box hanger system went through a number of variations with only one design seeing widespread use.
The box hanger that became standard issue was a right hand feed system that held a single 100 round ammunition box horizontally across the underside of the receiver. The belt fed up a covered tray and into the feed cover. A spring-loaded latch was on the inside of the hanger’s feed tray to keep the belt from slipping back into the ammunition box when the weapon wasn’t firing. This latch helped cut back on the strain on the feed mechanism.
A new style of quick-detachable mount was used to hold the standard box hanger in place underneath the receiver of the weapon. A spring-loaded plunger was squeezed to release the front latch, which fit over the forestock holding pin. The rear of the quick-detach mount had a curved protrusion that fit over the front pin of the trigger group. This box hanger only worked with a right-hand feed top cover and feed tray. But other systems were tried.
Both China Lake and Cadillac Gage made a variety of box hangers and drums to try and come up with the best ammunition holding system for the Stoner. Some left-hand feed box hangers were made, but these had the same spin-back problems as the drum. A 250-round belt drum was made in limited numbers at China Lake for testing by the SEALs. But the Stonermen who tried the 250-round drum found it was too large and unbalanced the weapon, making it clumsy to handle.
Other box hangers were tried that held 150 round plastic ammunition boxes or secured the ammunition belt under a long cover, hinged at the bottom. None of these systems found the acceptance of the right-hand feed, 100 round belt box hanger.
But with the belt box hanger came another new problem with loading the Stoner 63A. The cocking lever for the machine gun versions of the Stoner 63A was still in the same location as the lever for the earlier 63 model. The cocking lever had been made longer on the 63A, and was more secure to use. But the box hanger and the right hand feed interfered with the operator easily reaching the cocking handle to charge the weapon. The feed tray of the box hanger would block much of the cocking lever so that the operator could only reach the lever with one or two fingers.
To ease the cocking lever problem, a solution was taken from the carbine and rifle configurations of the Stoner 63A. The forestock for the Stoner 63A machine gun was modified with a wide, six-inch long slot cut in the bottom center of the handguard. The protruding rod cocking lever of the carbine and rifle versions was modified by removing the center plunger and installed under the barrel of the machine gun, fitting through the slot in the bottom of the handguard.
Now a Stoner gunner could use either hand to pull back the cocking rod, easily charging the machine gun with whatever feeding system the weapon might be mounted with. Some operators found the protruding cocking rod to be a little short for their comfort. A piece of tubing forced over the rod of the cocking piece would extend it several inches and satisfy the operators who thought it too small.
The size and weight of a weapon was always a consideration in the Teams. Even with its light weight, the SEALs wanted the Stoner to be made even more compact if possible. Using the carbine configuration barrel as a starting point, Cadillac Gage designed a short, heavy machine gun barrel for the SEALs in 1968.
This short barrel was heavier and larger in diameter than the carbine barrel, but was the same overall length. To cut down on the weight of the short machine gun barrel, the outside was fluted with six deep flutes cut lengthwise into the steel. The flutes removed some weight and increased the surface area of the barrel, allowing it to radiate heat better and cool quicker.
Referring to the new barrel as their “commando” model, Cadillac Gage began supplying the new part to the SEAls in 1968. The short barrel also had a gas port selector underneath the front sight, but this selector only had two settings. The commando barrel could be slipped onto any SEAL Stoner 63A, removing 6.25 inches of length and about 1.56 pounds of weight.
A short commando barrel, right hand feed top cover, and 150-round drum, assembles a Stoner 63A into what is considered the “classic” SEAL Stoner configuration. Most of the 63As in SEAL hands were modified with the new cocking system and the new right-hand feed mechanisms. The short commando barrel had some difficulties in operating the Stoner in certain environments. With the very short section of barrel, actually just the flash hider, in front of the gas port (underneath the front sight) there is very little residual gas pressure to operate the action of a Stoner fitted with the short barrel. The longer standard barrel maintained a higher gas pressure for a longer time when the weapon was fired. This allowed for a greater level of energy to be available to operate a dirty or sluggish action.
But a number of SEALs swore by the new short barrels and made sure that their Stoners remained as clean and well lubricated as possible. The advantage of the short commando barrel was that it made a compact weapon even smaller and easier to handle in the close brush and jungle. Some SEALs made the Stoner an even more compact weapon for close-in use by removing the buttstock completely and trying a piece of line onto the weapon to act as a sling.
The short commando barrel, right hand feed, and 100 round box hanger completed the final version of the SEAL Stoner. This weapon resulted from the input of the SEALs having used the Stoner in combat for almost two full years. In this final form, the Stoner received a nomenclature assignment by the Navy as the Mark 23 Mod 0. The original request for the nomenclature was submitted on 14 March 1969, Mark number assigned on 31 October 1969, and the final approval made on 4 December 1969. The description of the weapon on the assignment request was;
Gun, Machine, 5.56 Millimeter, Mark 23 Mod 0 …is a gas operated 5.56MM automatic weapon using disintegrating metallic belts, belt fed, fires from the open bolt position, has a quick change barrel, with right hand twist rifling (6 grooves) one turn in 12 inches, fires 700 to 1000 rounds per minute, with a muzzle velocity of 3256 feet per second. Giving a maximum range of 2895 yards (2653 meters), the maximum effective range is 1203 yards (1100 meters). The overall length is 40.25 inches. The gun empty weighs 11.68 pounds. Manufactured by Cadillac Gage Company, Roseville, Michigan. Company designation is 5.56M light machine gun, belt fed, Stoner 63A
The nomenclature assignment fit both the long and short barreled Stoner, with either the right or left hand feed. All Navy purchases of the Mark 23 Mod 0 were of the short-barreled, right hand feed versions with the 100 round box hanger. The Mark 23 was offered by Cadillac Gage to other military customers as the “Commando machine gun.”
The correct nomenclature of the final configuration of the SEAL Stoner becomes difficult at this point. The Mark 23 Mod 0 Stoner was referred to as the Stoner 63A in most Cadillac Gage literature and this was the designation used by SEAL Team Two.
Receiver markings on the Stoner series had not significantly changed during the entire production run except for the address of the company. All Cadillac Gage Stoners were marked STONER 63 .223 CAL. just in front of the serial number. All of the modifications requested by the SEALs and incorporated as a whole in the Mark 23 resulted in significant changes in the weapon. Both SEAL Team Two and Navy documentation refer to the Mark 23 as being known commercially as the Stoner 63A1.
NWM of Holland had licensed production of the Stoner weapons system for sale in Europe. Only a handful of the Dutch weapons were produced, reportedly on about 60 US made receivers. These weapons were advertised in a September 1969 booklet produced by NWM and titled the Stoner 63A1 Weapons Modifications. The machine gun configuration illustrated in the booklet, identified as the XM207, was identical to the Mark 23 except for an NWM designed bipod and mount and a long barrel.
The most numerous Stoners in SEAL hands were the Mark 23/63A1 weapons purchased by the Navy in 1969 and 1970.
SEAL TEAM TWO – COMMAND AND CONTROL HISTORIES
1969, Enclosure 1, VI NEW EQUIPMENT, pg 14
4. (U) During the year, the Team received twelve new Stoner 63A1 light machine guns which, although they are only half the operational quota requested, will help provide each platoon with greater firepower in the field.
SEAL TEAM TWO – COMMAND AND CONTROL HISTORIES
1970, Enclosure 1, VI. NEW EQUIPMENT, pg 12
3. (U) Twelve new Stoner 63A1 light machine guns were received. Each deployed platoon now has two of these weapons per squad.
Estimates according to available documents puts the number of Stoners purchased outright by the Navy for the SEALs at 8 Stoner 63s, 36 Stoner 63A’s, and 48 Stoner 63A1’s (as Mk 23’s). Additional Stoner receivers and systems may have been transferred into the Teams from the stocks of Marine weapons that had been turned in to storage.
With the final acceptance of the Mark 23 machine gun, no further purchases were made of parts for the Stoner 63’s that were in inventory or accessories that would fit the earlier weapons. This means that drums gradually became harder to find for those SEALs who preferred that method of loading. Though the drums were simple and had few parts, the method of securing the rear cover with a twist latch was subject to wear. This resulted in an increasing number of drums being sealed with tape prior to going out on an operation. This made reloading the drums very difficult in the field.
As a field-expedient solution, a number of SEALs modified a mount for the Stoner that would accept the ammunition drum from the Soviet RPD machine gun. The Soviet RPD used a stamped steel drum to contain a 100-round non-disintegrating metal belt of 7.62x39mm ammunition. The drums were commonly found in munitions caches and were available to the SEALs in some numbers.
Each RPD drum would hold a 150-round belt of Stoner ammunition easily, and feed it smoothly into the weapon. The quick-detachable mount portion of an ammunition box hanger could be removed by simply cutting away two rivets. A sheet metal extension would be locally fabricated and secured to the mount with two screws. The addition of a twist latch, such as used on a screen window, completed the mount. The RPD drum mount would fit underneath a Stoner and could be set up to feed into either a right or left-hand feed weapon. In addition, an empty RPD drum was easily and quickly exchanged for a loaded one to reload the weapon.
Throughout the Vietnam War, the Stoners were demonstrated to be a useful addition to the SEALs arsenal. But this didn’t come without a cost. Technical training on the Stoner weapons system was increased to help minimize problems with the weapon.
SEAL TEAM TWO – COMMAND AND CONTROL HISTORIES
1969, Enclosure (1) V. PREDEPLOYMENT TRAINING
Some members of deploying platoons…….received special training in the maintenance and use of the Stoner 63A1 light machine gun and the M16A1 rifle. The machine gun instruction was administered by the manufacturer of the weapon, Cadillac Gage Company, Detroit, Michigan
Any new weapons system has to go through a development process to locate and eliminate errors in the design. Sometimes these errors were located with little more than some difficult incidents for the operator.
The quick disconnect barrel of the Stoner was held in place with a push-button latch just in front of the feed cover. With the bolt cocked, the only thing holding the barrel in place was the barrel latch. If the latch had been depressed accidentally, such as while moving through brush on a patrol, as soon as the trigger was pulled, in forward moving bolt had as good a chance of pushing the barrel off of the weapon as it did of firing the cartridge it had stripped from the belt.
In spite of the general opinion the SEALs had about the Stoner, there had been some serious incidents with the weapon. One incident in particular almost resulted in the Navy dropping the weapon entirely. To field-strip the Stoner for cleaning, one step in the procedure is to remove a takedown pin found just above and behind the pistol grip, With the takedown pin withdrawn, the receiver can pivot up and away from the stock and trigger group. This allows the bolt and internal mechanism of the Stoner to be withdrawn.
With the Stoner machine gun operating from an open bolt and the sear which holds the bolt in the cocked position part of the trigger group, separating these parts with the bolt cocked will release it to drive forward. If there is a round in the feed tray, the weapon will fire. If there is a belt in the feed tray, the weapon will fire uncontrollably until either the belt runs out, or the bolt flies out of the back of the partially opened weapon. Something very close to this situation happened to a squad of SEALs from SEAL Team One while inserting on an operation.
Mike Platoon of SEAL Team One was operating in the Kien Hoa province of Vietnam, having moved down into the Mekong Delta area from the Rung Sat Special Zone just a short time earlier. On 29 April, 1968, the platoon was moving in for an insertion from a Mark 4 landing craft. The trip to the insertion point was an uneventful one up to a point. The SEALs were relaxing aboard the boat as was normal prior to an operation. One SEAL, Walter Pope, was armed with a Stoner 63A fitted with a 150 round drum. The Stoner was up, leaning against the side of the armored landing craft as the unit moved along the waterway.
It was never determined exactly what happened next, but the sudden results were that Pope’s Stoner fell over on its side as it began firing wildly. According to witnesses, Pope had not been touching the weapon when the incident began, but suddenly the Stoner was firing uncontrollably.
Frank Toms, reclining nearby, was half-asleep when the accident happened. He was suddenly awakened when he was struck with an estimated 6 to 10 bullets from the runaway Stoner. Walter Pope dove onto the firing Stoner and pulled it into himself to stop the firing and protect his teammates in the boat. Pope took an estimated 40 rounds from the Stoner but prevented any one else from being struck with the ricocheting rounds bouncing around inside the armored boat.
First Class Boatswain’s Mate Walter Pope was killed instantly, but saved his fellow SEALs in the boat. Frank Toms recovered from his wounds. The intense investigation that followed could only come up with the most probable reason the accident occurred. The take down pin on the trigger group of the Stoner at that time was retained by it’s own friction and a small spring detent in the pin itself. It is thought that the vibration from the boat’s engines and pitching of the craft in the water worked the takedown pin free of Pope’s Stoner.
Sitting as it was, muzzle up, the force of gravity as well as the spring tension inside the cocked weapon would have combined to separate the two parts of the receiver, releasing the bolt to drive forward. In this situation, the weapon would have continued firing until it had jammed or run out of ammunition.
As far as Frank Toms is concerned, Pope’s actions that day saved his Teammates and is deserving of the highest award that can be given. The SEALs were in immediate contact with Cadillac Gage about the incident, how it happened, and how to prevent it from ever happening again.
The pivot pin that held the feed cover to the receiver of the Stoner was secured in a different manner than the detent-held takedown pin. The pivot pin is made of two parts that screw together securely, and are further held together by a spring detent inside the body of the pin. It takes the point of a bullet to release the detent and then the two parts have to be unscrewed before the pin can be removed.
This pin was immediately supplied by Cadillac Gage to the Teams in sufficient quantities to replace all of the earlier pins in service. The field stripping procedure on the Stoners with the new pins took a little longer, but the accidental discharge of a weapon due to the receivers separating didn’t happen again.
The Stoner was not the only light machine gun used by the SEALs in Vietnam, But it was one of the most unique. All production of the Stoner ceased by 1971 and Cadillac Gage closed the records on the weapon system in 1973. The Stoner remained in the SEAL inventory until the early 1980’s. By 1983, the last few Stoners remaining in SEAL hands were removed from active duty due to a lack of parts and support to maintain the weapons in operating condition.
|This article first appeared in Small Arms Review V5N8 (May 2002)|
and was posted online on January 24, 2014