Stoner 63
Encyclopedia
The Stoner 63, also known as the XM22/E1, is an American modular weapons system designed by Eugene Stoner
in the early 1960s. It was produced by Cadillac Gage
and used in very limited numbers in Vietnam
by members of the United States Navy SEALs
and several law enforcement agencies.
Soon after leaving ArmaLite
, Eugene Stoner
, one of the United State's most prolific modern military small arms designers, responsible for the design of the AR-15
/M16
assault rifle
s, AR-10
battle rifle
and AR-5 survival rifle, among others, devised a concept for a weapons platform that would be built around a common receiver
and certain interchangeable components and could be transformed into a rifle, carbine
or various machine gun
configurations by simply fitting the appropriate parts to the basic assembly.
Stoner managed to solicit the help of Howard Carson, in charge of Cadillac Gage's West Coast plant in Costa Mesa
, California
(where Armalite was also located), in convincing the company's president, Rusell Baker, of the feasibility and commercial potential of his new weapons system. Russell obliged and Cadillac Gage (a subsidiary of the Ex-Cell-O Corporation) established a small arms development branch in Costa Mesa. Stoner then recruited his two principal aides at Armalite: Robert Fremont and James L. Sullivan (who would later go on to design the Ultimax 100
light machine gun
for the Chartered Industries of Singapore).
The first working prototype was chambered in 7.62x51mm NATO and completed in 1962. It was designated the Stoner M69W (for no other reason than when turned upside down it reads the same, symbolizing Stoner's vision of a fully invertible receiver). A second prototype called the Stoner 62 was fabricated before the team decided to focus on the promising new 5.56x45mm
small caliber high-velocity cartridge, as it appeared the new round was gaining mainstream military approval. At that time the weapon became known as the Stoner 63. No more than 200 guns were manufactured at the Costa Mesa facility before production was transferred to the Cadillac Gage plant in Warren
, Michigan
. The weapon is covered under .
at Quantico
for evaluation, where it made a positive impression with its light weight and high ammunition capacity; the Marines favored the rifle and light machine gun configurations. Trials were performed by the Army Material Command (responsible for logistical support for the Marine Corps) at their own test facilities.
Many bugs affected the outcome of the Army trials of the gun: the ammunition requirements proposed were unrealistic and the weapon was expected to perform with an extremely wide range of port pressures, leaving very little power reserve with some ammunition types. For instance, the tracer ammunition used in the Stoner 63 was of such low pressure that it even failed to function reliably in the M16.
These factors severely affected the weapon's reliability. After several months of testing, the Stoner 63 system was ultimately deemed to be unacceptable for service use. The Army submitted recommendations for improvements to the design—these included a stainless steel
gas cylinder, a two-position fire selector with separate safety, ejection port dust covers and modifications to the belt feed mechanism. The upgrades resulted in the improved Stoner 63A, which began production in 1966. Only about 2,000 examples of the initial version were manufactured before the transition to the model 63A.
Even very early on in its development stage, a small number of weapons were hurriedly pressed into service with the U.S. Navy SEALs deployed to Southeast Asia
. During 1967, the Stoner 63A system was field tested by Company L (Lima Company), 3rd Battalion
, 1st Marine Regiment, 1st Marine Division. Riflemen were issued the weapon in the Rifle configuration (in both 63 and 63A variants, designated XM22 and XM22E1 respectively), while officers and certain other personnel received the Carbine (XM23). The Automatic Rifle configuration was deployed on a limited basis in the squad automatic role, while Lima's weapons platoon received both the LMG and MMG configurations.
In 1967, Dutch
firm NWM (Nederlandsche Wapen-en Munitiefabriek) De Kruithoorn N.V. of 's-Hertogenbosch acquired licensing rights to manufacture and sell the weapon worldwide with the exception of the United States, Canada and Mexico. NWM assembled several prototypes but the company failed to secure any export customers and the weapon was withdrawn.
In 1970, the U.S. Army
designated the Commando configuration XM207 and issued it to select Army Special Forces
units for evaluation. However, due to its complexity and high maintenance requirements (especially when compared to the new M16), the design was rejected, and the project was dropped in 1971. Around 4,000 63 and 63A units were built in total. Most of them continued to see use by U.S. Navy SEAL teams, under the designation M63A1. However, by the late 1980s the Stoner 63 was completely phased out in favor of the new M249 SAW, and most of the remaining guns were destroyed. Today, surviving examples number in the dozens.
, air-cooled belt
or magazine-fed and fire from the open bolt
position to prevent cook-offs and enhance cooling. The weapon has a rotary bolt
locking mechanism with 7 radially symmetrical locking lugs that engage a series of recesses in the barrel
extension, and is actuated by a conventional long-stroke piston. The radial arrangement of locking lugs distributes the firing load evenly around the bolt head and barrel socket, reducing stress and increasing the longevity of these critical components. Attached to the piston extension is the bolt carrier which is equipped with a curved cam track that guides the bolt's cam pin (retained by the firing pin
) and rotates the bolt 22.5° during the movement of the piston to either lock or unlock the bolt from behind the abutments in the barrel socket. Incorporated into the bolt carrier/piston group is an anti-bounce device, consisting of a 4 in (10.2 cm) carbide
rod that rides within the piston extension’s hollow interior and moves back and forth during the recoil and counter-recoil cycles, reducing bolt bounce and preventing the possibility of firing out of battery during closed bolt firing (in the Rifle/Carbine models).
When fired, propellant gases from the ignited cartridge following the projectile down the bore are vented through a gas port into a gas cylinder where they drive the piston and bolt carrier rearward. There is about 0.2 in (0.508 cm) of uninterrupted free travel calculated to permit the gas build-up in the bore to drop to a safe level before the carrier's cam slot rotates the bolt counter-clockwise to unlock. The locking lugs have no pitch therefore no primary extraction occurs during the unlocking sequence. A deeply-seated spring-loaded claw extractor
in the bolt head extracts the spent cartridge casing from the chamber and a spring-powered ejector fixed to the front feed mechanism trigger housing ejects the casing. The bolt carrier continues to the rear and compresses the recoil spring on its guide rod.
The Stoner 63 has a unique buffering system contained within the bolt carrier. In front of the carrier cap are a steel
shim and a set of 27 saucer-shaped Belleville washer
s oriented in opposing sets of three, which absorb energy from the piston stroke by deforming into a flat plate when the bolt carrier strikes the receiver’s end cap. When the plates return to their original shape they release a pulse of strain energy
which propels the reciprocating parts forward in counter-recoil with a speed only slightly below that of the original recoil velocity. This feature was designed to extend the weapon’s service life, and the plates will function without failure for between 40,000 and 50,000 rounds (depending upon the type of ammunition used and cyclic rates employed).
The Stoner 63/63A is chambered for the now-standard 5.56x45mm intermediate rifle cartridge. When in the belt-fed role, the weapon would feed from a disintegrating metallic linked belt marked "S-63 BRW" which is a scaled-down version of the U.S. M13 link
developed for the M60
GPMG
. The Stoner 63/63A will not work reliably with the later M27 link developed for the M249 SAW. The belt is normally contained in a 150-round plastic ribbed container that has a tab allowing it to be clipped on to the side of the left-hand feed tray. Early ammunition boxes were olive drab in color and manufactured at Costa Mesa, this later changed to a black-colored plastic container made in Warren, Michigan. Stoner 63A boxes were also black but had a reduced capacity of 100 rounds as the larger container would unbalance the rifle. These can either be attached to the left-hand feed tray or held in a bottom box carrier when using the right-hand feed mechanism. Several drum-type belt carriers were designed for the left-hand feed system, with a 150-round drum container being the most popular and used frequently by SEALS in Vietnam. A 250-round drum carrier was also developed by NAWS China Lake
, but this proved too heavy and cumbersome. SEALS would also resort to converting RPD
belt carriers for use with their Stoners. The detachable magazines used in the Rifle, Carbine and Automatic Rifle models are fabricated from steel and weigh 8 oz (226.8 g) unloaded. In an effort to reduce weight, aluminum magazines were later developed cutting the weight down to 4 oz (113.4 g). Standard magazines have a 30-round cartridge capacity but a 20-round magazine was also offered.
). The Commando barrel has a length of 15.7 in (39.9 cm) and is fluted
to reduce weight and enhance the barrel's cooling characteristics. This version was sometimes used by the Navy SEALS but was never fully reliable as the gas port is near the muzzle and as soon as the bullet leaves the barrel, gas pressures drop drastically leaving the operating system little to no power reserve. The gas port was drilled larger in an attempt to alleviate this problem; however this had the effect of merely accelerating the piston's initial displacement. The issue was never truly resolved. The Rifle, Carbine and AR barrels have no gas valves as they are exclusively used in magazine-fed configurations and do not require the energy surplus levels of belt-fed mechanisms. The standard machine gun barrel has a manually adjustable gas regulator that can be operated by inserting the nose of a cartridge into a hole over the regulator’s lock detent, pushing down on the detent and rotating to the desired position. The gas regulator has three settings: a "slow" cyclic rate of about 700 rounds/min, produced when the narrowest indicator notch is set over the detent; a middle position with an intermediate rate of 830 rounds/min and a third "fouled" position that delivers the largest quantity of propellant gas to the system, resulting in a rate of fire of 865 rounds/min (the use of this setting should be limited as it induces excessive wear on the operating mechanism).
All Stoner 63/63A barrels are gas nitrided
and have a quick-detach capability and can be removed in a matter of seconds in field conditions by simply pushing down a latch located on top of the weapon in front of the feed cover and pulling the barrel forward (with the bolt retracted). The chamber portion of the barrel rests on a U-shaped barrel bracket attached to the gas cylinder. The barrel is firmly locked in position by means of a spring-loaded latch (with two nested coil springs) which drives a steel pin into a hole in the barrel socket. All barrels have a gas block to which a bayonet lug
and front sight assembly are mounted. The barrels are equipped with a bird cage type flash suppressor with six oval ports. The AR and standard machine gun barrels also have a carrying handle that can be snapped into one of three positions or removed altogether. The black-painted wooden handles are attached to a steel rod via roll pin. With a few exceptions, all the barrels used in the Stoner 63/63A have a six-groove right-hand rifling with a twist rate of 1:12 in (305 mm), designed to stabilize the lightweight 55-grain M193 projectile (standard at the time). However, after NWM had obtained a license to produce the Stoner 63A, some barrels were manufactured with a 1:8 (200 mm) in rifling pitch to be used with heavier experimental bullets. None of these were ever produced in significant numbers.
. The black polycarbonate
pistol grip
is also attached to the trigger housing. The checkered grip is flared at the bottom to prevent the shooter’s hand from sliding off and has an internal storage compartment sealed by a hinged cover with a spring-loaded hatch.
is typically mounted on the right side of the receiver. It has 24 lightening holes and engages a projection on the piston to draw the piston and bolt group to the rear (cocked) position. The handle should then be pushed back forward allowing a flat-spring latch riveted to the front end to capture a slotted plate welded to the front of the receiver. With the right-hand feed mechanism with underslung box carrier installed the handle is awkward to operate, so a special slotted forearm with a bottom cocking handle was developed.
The nucleus of the Stoner 63 system is the receiver which is a rectangular sheet metal
pressing. The gas cylinder, support structures, brackets, lugs and other devices are welded in place. The front portion carries the piston and barrel and is perforated to reduce weight and improve air circulation around the barrel and gas cylinder. The rear segment holds the piston extension and bolt group. The ejection port is on the right side when the receiver is inverted and the weapon is configured as a rifle or carbine and on the left side when in the various machine gun roles. The various components are phosphate finished
and then coated with a black baked enamel
finish called Endurion. Early examples of the Stoner 63 were delivered with all wood furniture, however these were soon replaced with black polycarbonate parts with the exception of the handguard, which remained wood, but was painted black.
The Stoner 63 bipod
is a non-locking type that attaches to the gas tube; it does not pivot and has a limited height adjustment feature. The Stoner 63A bipod is extensively perforated with lightening holes and can be locked in either the stowed or deployed positions. It too does not pivot but is compatible with the earlier Stoner 63, whereas the Stoner 63 bipod will not work with the later 63A pattern guns as the gas tube is of a larger diameter.
increments. When the primary sight is folded down, a battle sight aperture with a diameter of 0.09 in (0.2286 cm) is exposed. The Rifle and Carbine versions have simple flip-type apertures with settings for 0–300 and 300–500 m contained between large perforated protective ears. The sights are adjustable in both windage and elevation in 1 MOA
increments. All variants share the same front sight assembly—a semi-shrouded round threaded post adjustable for windage and elevation zero (similar to the M16 front sight).
-lined spare barrel bag, cleaning kit, 40 mm grenade launcher
, several types of sling
s and a wide range of belt box and magazine pouches.
The Stoner 63/63A used three different types of bayonet
s: the standard U.S. M7
, the KCB 70, developed specifically for this rifle by the West German company Eickhorn-Solingen together with NWM and a rare bayonet made by the Swiss
industrial conglomerate SIG
. The KCB 70 features a 7 inches (177.8 mm) long Bowie blade with a clip-point and an integrated wire-cutter, it was inspired by Soviet
bayonets for the AKM
. A highly successful multi-purpose tool that was a far superior field knife to the M7, it evolved into the KCB 77, a modular design that was adapted to many different assault rifles.
, an assault rifle
, and various light machine gun
s feeding linked ammunition
from the left or right. The gas system was mounted in different positions depending on the weapon's configuration. Due to the multi-role nature of the design the carbine and rifle versions were heavier than comparable weapons of the same type.
The most recent descendant of this line is the Stoner LMG
produced by Knight's Armament Company
, which has significant changes from the older Stoner 63.
Robinson Armament Co.
also produces the semi-automatic
M96 Expeditionary Weapon System which, though technically different, was based on the Stoner 63 design, and thus has some of its features and configurations.
Also to note a bullpup conversion was made from AR-18 assault rifles by Enfield when developing the SA80.
Eugene Stoner
Eugene Morrison Stoner is the man most associated with the design of the AR-15, which was adopted by the US military as the M16...
in the early 1960s. It was produced by Cadillac Gage
Cadillac Gage
Textron Marine & Land Systems is an American military contractor that manufactures armored vehicles, turrets, advanced marine craft, surface effects ships, and other weapon systems...
and used in very limited numbers in Vietnam
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
by members of the United States Navy SEALs
United States Navy SEALs
The United States Navy's Sea, Air and Land Teams, commonly known as Navy SEALs, are the U.S. Navy's principal special operations force and a part of the Naval Special Warfare Command as well as the maritime component of the United States Special Operations Command.The acronym is derived from their...
and several law enforcement agencies.
Development
ArmaLite
ArmaLite is the name of a small arms engineering facility founded in the early 1950s, and once associated with the Fairchild Engine and Airplane Corporation. ArmaLite was formally incorporated as a subdivision of Fairchild on October 1, 1954...
, Eugene Stoner
Eugene Stoner
Eugene Morrison Stoner is the man most associated with the design of the AR-15, which was adopted by the US military as the M16...
, one of the United State's most prolific modern military small arms designers, responsible for the design of the AR-15
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
/M16
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
assault rifle
Assault rifle
An assault rifle is a selective fire rifle that uses an intermediate cartridge and a detachable magazine. Assault rifles are the standard infantry weapons in most modern armies...
s, AR-10
AR-10
The AR-10 is an American 7.62 mm battle rifle developed by Eugene Stoner in the late 1950s at ArmaLite, then a division of the Fairchild Aircraft Corporation...
battle rifle
Battle rifle
A battle rifle is a military service rifle that fires a full power rifle cartridge, such as 7.62x51mm NATO. While the designation of battle rifle is usually given to post-World War II select fire infantry rifles such as the H&K G3, the FN FAL or the M14, this term can also apply to older military...
and AR-5 survival rifle, among others, devised a concept for a weapons platform that would be built around a common receiver
Receiver (firearms)
In firearms terminology, the receiver is the part of a firearm that houses the operating parts. The receiver usually contains the bolt carrier group, trigger group, and magazine port. In most handguns, the receiver, or frame, holds the magazine well or rotary magazine as well as the trigger mechanism...
and certain interchangeable components and could be transformed into a rifle, carbine
Carbine
A carbine , from French carabine, is a longarm similar to but shorter than a rifle or musket. Many carbines are shortened versions of full rifles, firing the same ammunition at a lower velocity due to a shorter barrel length....
or various machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
configurations by simply fitting the appropriate parts to the basic assembly.
Stoner managed to solicit the help of Howard Carson, in charge of Cadillac Gage's West Coast plant in Costa Mesa
Costa Mesa, California
Costa Mesa is a city in Orange County, California. The population was 109,960 at the 2010 census. Since its incorporation in 1953, the city has grown from a semi-rural farming community of 16,840 to a primarily suburban and "edge" city with an economy based on retail, commerce, and light...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
(where Armalite was also located), in convincing the company's president, Rusell Baker, of the feasibility and commercial potential of his new weapons system. Russell obliged and Cadillac Gage (a subsidiary of the Ex-Cell-O Corporation) established a small arms development branch in Costa Mesa. Stoner then recruited his two principal aides at Armalite: Robert Fremont and James L. Sullivan (who would later go on to design the Ultimax 100
Ultimax 100
The Ultimax 100 is a Singaporean 5.56mm light machine gun, developed by the Chartered Industries of Singapore by a team of engineers under the guidance of American firearms designer L. James Sullivan. The gun is extremely accurate due to its low recoil.Work on a new light support weapon for the...
light machine gun
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
for the Chartered Industries of Singapore).
The first working prototype was chambered in 7.62x51mm NATO and completed in 1962. It was designated the Stoner M69W (for no other reason than when turned upside down it reads the same, symbolizing Stoner's vision of a fully invertible receiver). A second prototype called the Stoner 62 was fabricated before the team decided to focus on the promising new 5.56x45mm
5.56x45mm NATO
5.56×45mm NATO is a rifle cartridge developed in the United States and originally chambered in the M16 rifle. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries. It is derived from, but not identical to, the .223 Remington cartridge...
small caliber high-velocity cartridge, as it appeared the new round was gaining mainstream military approval. At that time the weapon became known as the Stoner 63. No more than 200 guns were manufactured at the Costa Mesa facility before production was transferred to the Cadillac Gage plant in Warren
Warren, Michigan
Warren is a city in Macomb County in the U.S. state of Michigan. The 2010 census places the city's population at 134,056, making Warren the largest city in Macomb County, the third largest city in Michigan, and Metro Detroit's largest suburb....
, Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
. The weapon is covered under .
Trials
In August and September 1963, the Stoner 63 was sent to the Marines Corps Landing Force Development CenterUnited States Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...
at Quantico
Quantico, Virginia
- Demographics :As of the census of 2000, there are 561 people, 295 households, and 107 families living in the town. The population density is . There are 359 housing units at an average density of .-Racial composition:...
for evaluation, where it made a positive impression with its light weight and high ammunition capacity; the Marines favored the rifle and light machine gun configurations. Trials were performed by the Army Material Command (responsible for logistical support for the Marine Corps) at their own test facilities.
Many bugs affected the outcome of the Army trials of the gun: the ammunition requirements proposed were unrealistic and the weapon was expected to perform with an extremely wide range of port pressures, leaving very little power reserve with some ammunition types. For instance, the tracer ammunition used in the Stoner 63 was of such low pressure that it even failed to function reliably in the M16.
These factors severely affected the weapon's reliability. After several months of testing, the Stoner 63 system was ultimately deemed to be unacceptable for service use. The Army submitted recommendations for improvements to the design—these included a stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
gas cylinder, a two-position fire selector with separate safety, ejection port dust covers and modifications to the belt feed mechanism. The upgrades resulted in the improved Stoner 63A, which began production in 1966. Only about 2,000 examples of the initial version were manufactured before the transition to the model 63A.
Deployment
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. During 1967, the Stoner 63A system was field tested by Company L (Lima Company), 3rd Battalion
3rd Battalion 1st Marines
3rd Battalion 1st Marines is an infantry battalion in the United States Marine Corps based out of Camp Horno on Marine Corps Base Camp Pendleton, California...
, 1st Marine Regiment, 1st Marine Division. Riflemen were issued the weapon in the Rifle configuration (in both 63 and 63A variants, designated XM22 and XM22E1 respectively), while officers and certain other personnel received the Carbine (XM23). The Automatic Rifle configuration was deployed on a limited basis in the squad automatic role, while Lima's weapons platoon received both the LMG and MMG configurations.
In 1967, Dutch
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
firm NWM (Nederlandsche Wapen-en Munitiefabriek) De Kruithoorn N.V. of 's-Hertogenbosch acquired licensing rights to manufacture and sell the weapon worldwide with the exception of the United States, Canada and Mexico. NWM assembled several prototypes but the company failed to secure any export customers and the weapon was withdrawn.
In 1970, the U.S. Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
designated the Commando configuration XM207 and issued it to select Army Special Forces
United States Army Special Forces
The United States Army Special Forces, also known as the Green Berets because of their distinctive service headgear, are a special operations force tasked with six primary missions: unconventional warfare, foreign internal defense, special reconnaissance, direct action, hostage rescue, and...
units for evaluation. However, due to its complexity and high maintenance requirements (especially when compared to the new M16), the design was rejected, and the project was dropped in 1971. Around 4,000 63 and 63A units were built in total. Most of them continued to see use by U.S. Navy SEAL teams, under the designation M63A1. However, by the late 1980s the Stoner 63 was completely phased out in favor of the new M249 SAW, and most of the remaining guns were destroyed. Today, surviving examples number in the dozens.
Operating mechanism
The Stoner 63 series of weapons are gas-operatedGas-operated reloading
Gas-operation is a system of operation used to provide energy to operate autoloading firearms. In gas-operation, a portion of high pressure gas from the cartridge being fired is used to power a mechanism to extract the spent case and chamber a new cartridge. Energy from the gas is harnessed...
, air-cooled belt
Belt (firearm)
A belt or ammunition belt is a device used to retain and feed cartridges into a firearm. Belts and the associated feed systems are typically employed to feed machine guns or other automatic weapons...
or magazine-fed and fire from the open bolt
Open bolt
A semi or full automatic firearm is said to fire from an open bolt if, when ready to fire, the bolt and working parts are held to the rear. When the trigger is pulled the bolt goes forward, feeding a round from the magazine into the chamber and firing it...
position to prevent cook-offs and enhance cooling. The weapon has a rotary bolt
Rotating bolt
Rotating bolt is a method of locking originally developed by Ferdinand Ritter von Mannlicher and found in his Steyr-Mannlicher M1895 straight-pull bolt-action rifle designed for and issued to the Austro-Hungarian Army...
locking mechanism with 7 radially symmetrical locking lugs that engage a series of recesses in the barrel
Gun barrel
A gun barrel is the tube, usually metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity....
extension, and is actuated by a conventional long-stroke piston. The radial arrangement of locking lugs distributes the firing load evenly around the bolt head and barrel socket, reducing stress and increasing the longevity of these critical components. Attached to the piston extension is the bolt carrier which is equipped with a curved cam track that guides the bolt's cam pin (retained by the firing pin
Firing pin
A firing pin or striker is part of the firing mechanism used in a firearm or explosive device e.g. an M14 landmine or bomb fuze. Firing pins may take many forms, though the types used in landmines, bombs, grenade fuzes or other single-use devices generally have a sharpened point...
) and rotates the bolt 22.5° during the movement of the piston to either lock or unlock the bolt from behind the abutments in the barrel socket. Incorporated into the bolt carrier/piston group is an anti-bounce device, consisting of a 4 in (10.2 cm) carbide
Carbide
In chemistry, a carbide is a compound composed of carbon and a less electronegative element. Carbides can be generally classified by chemical bonding type as follows: salt-like, covalent compounds, interstitial compounds, and "intermediate" transition metal carbides...
rod that rides within the piston extension’s hollow interior and moves back and forth during the recoil and counter-recoil cycles, reducing bolt bounce and preventing the possibility of firing out of battery during closed bolt firing (in the Rifle/Carbine models).
When fired, propellant gases from the ignited cartridge following the projectile down the bore are vented through a gas port into a gas cylinder where they drive the piston and bolt carrier rearward. There is about 0.2 in (0.508 cm) of uninterrupted free travel calculated to permit the gas build-up in the bore to drop to a safe level before the carrier's cam slot rotates the bolt counter-clockwise to unlock. The locking lugs have no pitch therefore no primary extraction occurs during the unlocking sequence. A deeply-seated spring-loaded claw extractor
Extractor (firearms)
An extractor is a part in a firearm that serves to remove brass cases of fired ammunition after the ammunition has been fired. When the gun's action cycles, the extractor lifts or removes the spent brass casing from the firing chamber.-Overview:...
in the bolt head extracts the spent cartridge casing from the chamber and a spring-powered ejector fixed to the front feed mechanism trigger housing ejects the casing. The bolt carrier continues to the rear and compresses the recoil spring on its guide rod.
The Stoner 63 has a unique buffering system contained within the bolt carrier. In front of the carrier cap are a steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
shim and a set of 27 saucer-shaped Belleville washer
Belleville washer
A Belleville washer, also known as a coned-disc spring, conical spring washer, disc spring, Belleville spring or cupped spring washer, is a type of spring shaped like a washer. It has a frusto-conical shape which gives the washer a spring characteristic. The Belleville name comes from the inventor...
s oriented in opposing sets of three, which absorb energy from the piston stroke by deforming into a flat plate when the bolt carrier strikes the receiver’s end cap. When the plates return to their original shape they release a pulse of strain energy
Strain energy
In a molecule, strain energy is released when the constituent atoms are allowed to rearrange themselves in a chemical reaction or a change of chemical conformation in a way that:* angle strain,* torsional strain,* ring strain and/or steric strain,...
which propels the reciprocating parts forward in counter-recoil with a speed only slightly below that of the original recoil velocity. This feature was designed to extend the weapon’s service life, and the plates will function without failure for between 40,000 and 50,000 rounds (depending upon the type of ammunition used and cyclic rates employed).
Feeding
In the belt-fed configuration, belt movement is produced by a roller riding in the channeled feed arm and is actuated by the reciprocating movement of the bolt. The spring-loaded feed arm is protected by a hinged top cover and is pivoted at its rear end. As the bolt travels back, the front end of the feed arm moves across the feed tray and operates a lever attached to a single set of spring-loaded pawls. These pawls move a cartridge and link over the feed tray’s stop pawl from where they are positioned onto the slotted feed path and held firmly in place by a spring-powered steel plate in the top cover. The cartridge is then pushed out of its link and the empty link is discarded through the link ejection port which is held closed by a spring-loaded dust cover.The Stoner 63/63A is chambered for the now-standard 5.56x45mm intermediate rifle cartridge. When in the belt-fed role, the weapon would feed from a disintegrating metallic linked belt marked "S-63 BRW" which is a scaled-down version of the U.S. M13 link
M13 link
The M13 link, formally Link, M13, is the U.S. military designation for a disintegrating metallic link specifically designed for belt-fed firearms and rounds; it was introduced in the mid-20th century. It is the primary link type for the U.S., and among NATO for 7.62 mm ammunition...
developed for the M60
M60 machine gun
The M60 is a family of American general-purpose machine guns firing 7.62×51mm NATO cartridges from a disintegrating belt of M13 links...
GPMG
General purpose machine gun
A general-purpose machine gun is a multi-purpose weapon: it is a machine gun firing a full-power rifle cartridge and which can be used in a variety of roles, from a bipod- or tripod-mounted infantry support weapon to a helicopter door gun or a vehicle-mounted support weapon...
. The Stoner 63/63A will not work reliably with the later M27 link developed for the M249 SAW. The belt is normally contained in a 150-round plastic ribbed container that has a tab allowing it to be clipped on to the side of the left-hand feed tray. Early ammunition boxes were olive drab in color and manufactured at Costa Mesa, this later changed to a black-colored plastic container made in Warren, Michigan. Stoner 63A boxes were also black but had a reduced capacity of 100 rounds as the larger container would unbalance the rifle. These can either be attached to the left-hand feed tray or held in a bottom box carrier when using the right-hand feed mechanism. Several drum-type belt carriers were designed for the left-hand feed system, with a 150-round drum container being the most popular and used frequently by SEALS in Vietnam. A 250-round drum carrier was also developed by NAWS China Lake
Naval Air Weapons Station China Lake
- About : is part of under Commander, Navy Installation Command and is located in the Western Mojave Desert region of California, approximately north of Los Angeles. Occupying three counties – Kern, San Bernardino and Inyo – the installation’s closest neighbors are the cities of Ridgecrest,...
, but this proved too heavy and cumbersome. SEALS would also resort to converting RPD
RPD
The RPD is a 7.62mm light machine gun developed in the Soviet Union by Vasily Degtyaryov for the intermediate 7.62x39mm M43 cartridge. It was created as a replacement for the DP machine gun chambered for the 7.62x54mmR Mosin rifle round...
belt carriers for use with their Stoners. The detachable magazines used in the Rifle, Carbine and Automatic Rifle models are fabricated from steel and weigh 8 oz (226.8 g) unloaded. In an effort to reduce weight, aluminum magazines were later developed cutting the weight down to 4 oz (113.4 g). Standard magazines have a 30-round cartridge capacity but a 20-round magazine was also offered.
Barrel
Barrel interchangeability is one of the main features that provides the Stoner 63 platform its outstanding versatility. There are 5 barrel options available for the system: the Rifle, Carbine, Automatic Rifle (AR) and two types of machine gun barrels, a standard heavy barrel and a short Commando tube. The standard machine gun and AR barrels are 20 in (50.8 cm) in length (not including the flash suppressorFlash suppressor
A flash suppressor, also known as a flash guard, flash eliminator, flash hider, or flash cone, is a device attached to the muzzle of a rifle or other gun that reduces the visible signature of the burning gases that exit the muzzle. This reduces the chances that the shooter will be blinded in dark...
). The Commando barrel has a length of 15.7 in (39.9 cm) and is fluted
Fluting (firearms)
In firearms terminology, fluting refers to the removal of material from a cylindrical surface, usually creating grooves. This is most often the barrel of a rifle, though it may also refer to the cylinder of a revolver or the bolt of a bolt action rifle....
to reduce weight and enhance the barrel's cooling characteristics. This version was sometimes used by the Navy SEALS but was never fully reliable as the gas port is near the muzzle and as soon as the bullet leaves the barrel, gas pressures drop drastically leaving the operating system little to no power reserve. The gas port was drilled larger in an attempt to alleviate this problem; however this had the effect of merely accelerating the piston's initial displacement. The issue was never truly resolved. The Rifle, Carbine and AR barrels have no gas valves as they are exclusively used in magazine-fed configurations and do not require the energy surplus levels of belt-fed mechanisms. The standard machine gun barrel has a manually adjustable gas regulator that can be operated by inserting the nose of a cartridge into a hole over the regulator’s lock detent, pushing down on the detent and rotating to the desired position. The gas regulator has three settings: a "slow" cyclic rate of about 700 rounds/min, produced when the narrowest indicator notch is set over the detent; a middle position with an intermediate rate of 830 rounds/min and a third "fouled" position that delivers the largest quantity of propellant gas to the system, resulting in a rate of fire of 865 rounds/min (the use of this setting should be limited as it induces excessive wear on the operating mechanism).
All Stoner 63/63A barrels are gas nitrided
Ferritic nitrocarburizing
Ferritic nitrocarburizing is a range of case hardening processes that diffuse nitrogen and carbon into ferrous metals at sub-critical temperatures. The processing temperature ranges from to , but usually occurs at...
and have a quick-detach capability and can be removed in a matter of seconds in field conditions by simply pushing down a latch located on top of the weapon in front of the feed cover and pulling the barrel forward (with the bolt retracted). The chamber portion of the barrel rests on a U-shaped barrel bracket attached to the gas cylinder. The barrel is firmly locked in position by means of a spring-loaded latch (with two nested coil springs) which drives a steel pin into a hole in the barrel socket. All barrels have a gas block to which a bayonet lug
Bayonet lug
A bayonet lug is a standard feature on most military muskets, rifles, and shotguns, and on some civilian longarms. It is intended for attaching a bayonet, which is typically a long spike or thrusting knife...
and front sight assembly are mounted. The barrels are equipped with a bird cage type flash suppressor with six oval ports. The AR and standard machine gun barrels also have a carrying handle that can be snapped into one of three positions or removed altogether. The black-painted wooden handles are attached to a steel rod via roll pin. With a few exceptions, all the barrels used in the Stoner 63/63A have a six-groove right-hand rifling with a twist rate of 1:12 in (305 mm), designed to stabilize the lightweight 55-grain M193 projectile (standard at the time). However, after NWM had obtained a license to produce the Stoner 63A, some barrels were manufactured with a 1:8 (200 mm) in rifling pitch to be used with heavier experimental bullets. None of these were ever produced in significant numbers.
Fire control
The Stoner 63/63A LMG is an automatic weapon that fires from the open bolt and the trigger mechanism permits only fully automatic firing though burst size can be controlled by the shooter. The entire trigger unit has four trigger pins that give the unit its modularity. The front pin holds a flapper-type magazine catch/release (used in the Rifle/Carbine variants and the left-hand feed LMG with a 150-round drum-type belt container), a full dust cover (used with the top-feeding Automatic Rifle or vertically mounted ammo box on any belt-fed system) or a half size dust cover (used with the right-hand-feed bottom box carrier). The next two pins retain the timer and hammer, both of which are absent in the open bolt configurations. The final pin acts as the trigger’s axis shaft; the spring-loaded sear pivots on the selector lever’s axis pin. The selector is disconnected when firing from the open bolt and a sliding manual safety installed near the trigger guard disables the trigger when pushed to the rear. The rear portion of the trigger housing serves as a receiver end cap and is used to attach the shoulder stockStock (firearm)
A stock, also known as a buttstock or shoulder stock, is a part of a rifle or other firearm, to which the barrel and firing mechanism are attached, that is held against one's shoulder when firing the gun. Stocks are also found on crossbows though a crossbow stock is more properly referred to as a...
. The black polycarbonate
Polycarbonate
PolycarbonatePhysical PropertiesDensity 1.20–1.22 g/cm3Abbe number 34.0Refractive index 1.584–1.586FlammabilityV0-V2Limiting oxygen index25–27%Water absorption – Equilibrium0.16–0.35%Water absorption – over 24 hours0.1%...
pistol grip
Pistol grip
On a firearm or other tool, the pistol grip is that portion of the mechanism that is held by the hand and orients the hand in a forward, vertical orientation, similar to the position one would take with a conventional pistol such as the M1911....
is also attached to the trigger housing. The checkered grip is flared at the bottom to prevent the shooter’s hand from sliding off and has an internal storage compartment sealed by a hinged cover with a spring-loaded hatch.
Features
The hooked, non-reciprocating steel charging handleCocking handle
The cocking handle is a device on a firearm which, when operated, results in the hammer or striker being cocked or moved to the ready position...
is typically mounted on the right side of the receiver. It has 24 lightening holes and engages a projection on the piston to draw the piston and bolt group to the rear (cocked) position. The handle should then be pushed back forward allowing a flat-spring latch riveted to the front end to capture a slotted plate welded to the front of the receiver. With the right-hand feed mechanism with underslung box carrier installed the handle is awkward to operate, so a special slotted forearm with a bottom cocking handle was developed.
The nucleus of the Stoner 63 system is the receiver which is a rectangular sheet metal
Sheet metal
Sheet metal is simply metal formed into thin and flat pieces. It is one of the fundamental forms used in metalworking, and can be cut and bent into a variety of different shapes. Countless everyday objects are constructed of the material...
pressing. The gas cylinder, support structures, brackets, lugs and other devices are welded in place. The front portion carries the piston and barrel and is perforated to reduce weight and improve air circulation around the barrel and gas cylinder. The rear segment holds the piston extension and bolt group. The ejection port is on the right side when the receiver is inverted and the weapon is configured as a rifle or carbine and on the left side when in the various machine gun roles. The various components are phosphate finished
Phosphate conversion coating
Phosphate coatings are used on steel parts for corrosion resistance, lubricity, or as a foundation for subsequent coatings or painting. It serves as a conversion coating in which a dilute solution of phosphoric acid and phosphate salts is applied via spraying or immersion and chemically reacts with...
and then coated with a black baked enamel
Enamel paint
Enamel paint is paint that air dries to a hard, usually glossy, finish, used for coating surfaces that are outdoors or otherwise subject to hard wear or variations in temperature; it should not be confused with decorated objects in "painted enamel", where vitreous enamel is applied with brushes and...
finish called Endurion. Early examples of the Stoner 63 were delivered with all wood furniture, however these were soon replaced with black polycarbonate parts with the exception of the handguard, which remained wood, but was painted black.
The Stoner 63 bipod
Bipod
A bipod is a support device that is similar to a tripod or monopod, but with two legs. It provides significant stability along two axes of motion .-Firearms:...
is a non-locking type that attaches to the gas tube; it does not pivot and has a limited height adjustment feature. The Stoner 63A bipod is extensively perforated with lightening holes and can be locked in either the stowed or deployed positions. It too does not pivot but is compatible with the earlier Stoner 63, whereas the Stoner 63 bipod will not work with the later 63A pattern guns as the gas tube is of a larger diameter.
Sights
The sight arrangement on the Stoner 63/63A differs amongst the various configurations. On the belt-fed LMGs, the rear sights are mounted on the top cover. These consist of a folding leaf aperture elevation scale graduated in 100 m increments from 200 to 1,000 m. The rear sight can also be corrected for windage in ¼-milAngular mil
An angular mil, also mil, is a unit of angle. All versions of the angular mil are approximately the same size as a trigonometric milliradian.-History:The milliradian was first identified in the mid nineteenth Century...
increments. When the primary sight is folded down, a battle sight aperture with a diameter of 0.09 in (0.2286 cm) is exposed. The Rifle and Carbine versions have simple flip-type apertures with settings for 0–300 and 300–500 m contained between large perforated protective ears. The sights are adjustable in both windage and elevation in 1 MOA
Minute of arc
A minute of arc, arcminute, or minute of angle , is a unit of angular measurement equal to one sixtieth of one degree. In turn, a second of arc or arcsecond is one sixtieth of one minute of arc....
increments. All variants share the same front sight assembly—a semi-shrouded round threaded post adjustable for windage and elevation zero (similar to the M16 front sight).
Accessories
The Stoner 63/63A is supplied with several accessories, including: a blank-firing attachment (BFA), winter trigger guard, asbestosAsbestos
Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...
-lined spare barrel bag, cleaning kit, 40 mm grenade launcher
Grenade launcher
A grenade launcher or grenade discharger is a weapon that launches a grenade with more accuracy, higher velocity, and to greater distances than a soldier could throw it by hand....
, several types of sling
Sling
The word sling may refer to:* Sling , a device used to hurl projectiles* Sling is an item of climbing equipment consisting of a sewn loop of webbing that can be wrapped around sections of rock or tied to other pieces of equipment.* Sling * Ski jumping sling is an item of sports training...
s and a wide range of belt box and magazine pouches.
The Stoner 63/63A used three different types of bayonet
Bayonet
A bayonet is a knife, dagger, sword, or spike-shaped weapon designed to fit in, on, over or underneath the muzzle of a rifle, musket or similar weapon, effectively turning the gun into a spear...
s: the standard U.S. M7
M7 Bayonet
The M7 Bayonet is a bayonet that was used by the U.S. military for the M16 rifle, it can also be used for the AR-15 rifle. It was introduced in 1964, when the M16 entered service during the Vietnam War....
, the KCB 70, developed specifically for this rifle by the West German company Eickhorn-Solingen together with NWM and a rare bayonet made by the Swiss
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
industrial conglomerate SIG
Schweizerische Industrie Gesellschaft
Schweizerische Industrie Gesellschaft , or SIG, is the former name of SIG Holding AG, a Swiss company that has been active in various businesses during its more than 150 years of operation. Since the year 2000 the Society has undergone strategic refocus, concentrating on its core compentence in...
. The KCB 70 features a 7 inches (177.8 mm) long Bowie blade with a clip-point and an integrated wire-cutter, it was inspired by Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
bayonets for the AKM
AKM
The AKM is a 7.62mm assault rifle designed by Mikhail Kalashnikov. It is an upgraded version of the AK-47 rifle and was developed in the 1950s....
. A highly successful multi-purpose tool that was a far superior field knife to the M7, it evolved into the KCB 77, a modular design that was adapted to many different assault rifles.
Variants
The Stoner 63 was produced in several configurations, with 15 separate assemblies, which had limited parts commonality. These variants included a carbineCarbine
A carbine , from French carabine, is a longarm similar to but shorter than a rifle or musket. Many carbines are shortened versions of full rifles, firing the same ammunition at a lower velocity due to a shorter barrel length....
, an assault rifle
Assault rifle
An assault rifle is a selective fire rifle that uses an intermediate cartridge and a detachable magazine. Assault rifles are the standard infantry weapons in most modern armies...
, and various light machine gun
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
s feeding linked ammunition
Belt (firearm)
A belt or ammunition belt is a device used to retain and feed cartridges into a firearm. Belts and the associated feed systems are typically employed to feed machine guns or other automatic weapons...
from the left or right. The gas system was mounted in different positions depending on the weapon's configuration. Due to the multi-role nature of the design the carbine and rifle versions were heavier than comparable weapons of the same type.
- Stoner 63/63A Rifle: A standard assault rifle fed from below by a 30-round box magazine. Spent cases are ejected to the right. The cocking handle and gas system are mounted above the barrel. Unlike the belt-fed configurations, the Rifle fires from closed boltClosed boltA semi or full-automatic firearm which is said to fire from a closed bolt is one where, when ready to fire, a round is in the chamber and the bolt and working parts are forward...
. The rifle configuration was field tested by the USMC for a short period during 1967. It was eventually fitted with a lightweight bipod that folded beneath the handguard. - Stoner 63/63A Carbine: The Carbine is similar to the Rifle configuration, but with a shorter barrel and a folding shoulder stock. The carbine configuration was field tested by the USMC for a short period during 1967.
- Stoner 63/63A Automatic Rifle: The Automatic Rifle is a open-bolt rifle fed from a top-mounted, 30-round magazine. The front and rear sights are offset to the left to compensate for the magazine's position. The AR does not have a semi-automatic mode. The automatic rifle configuration was field tested by the USMC for a short period during 1967.
- Stoner 63/63A Light Machine Gun: The LMG configuration fires from an open bolt and is fed from the right-hand side by linked ammunition contained in a 100-round plastic box. The receiver is identical to the Rifle variants, but is inverted, so that spent cases and links are ejected to the left. The LMG has a quick-change barrel and the gas cylinder is positioned below the barrel since the receiver is inverted. The LMG configuration was adopted for military use by Navy SEAL units operating in Southeast Asia.
- Stoner 63/63A Medium Machine Gun: Identical to the LMG configuration. The difference is that the MMG comes with a separate adapter than can be used to attach the weapon to an M2M2 TripodThe M2 Tripod is a U.S. machine gun tripod originally used with the Browning M1919 infantry machine gun. Since then, it has seen several redesigns, but remained largely the same. In this fashion, the M2 tripod has seen combat service in every conflict the U.S. Army and Marine Corps has been...
or M122 tripodM122 tripodThe M122 tripod is a weapon mount used on the M60, M240 and M249 series machine guns. The M122 weighs 7.3 kilograms . The M122 tripod has started to be replaced by the M192 Lightweight Ground Mount, an advanced lightweight tripod fielded in the early 2000s....
. - Stoner 63/63A Fixed Machine Gun: Internally identical to the LMG configuration. Externally, the front sights, rear sights, foregrip and pistol grip are all removed. The trigger is activated remotely by a 24V solenoidSolenoidA solenoid is a coil wound into a tightly packed helix. In physics, the term solenoid refers to a long, thin loop of wire, often wrapped around a metallic core, which produces a magnetic field when an electric current is passed through it. Solenoids are important because they can create...
. The FMG was designed for use with the Cadillac Gage Commando APC, but was never officially adopted.
- Stoner 63/63A Commando: The Commando is a derivative of the LMG configuration. It is fed from the right by a 100-round drum magazine clipped below the receiver. The cocking handle is mounted underneath the foregrip for easier access. To save weight, the Commando eschews the quick-change barrel found on the other belt-fed configurations. This variant was used by some United States Navy SEALUnited States Navy SEALsThe United States Navy's Sea, Air and Land Teams, commonly known as Navy SEALs, are the U.S. Navy's principal special operations force and a part of the Naval Special Warfare Command as well as the maritime component of the United States Special Operations Command.The acronym is derived from their...
units in Vietnam. - Stoner 63 Survival Rifle: The Survival Rifle was designed in 1964 to compete with the Colt Model 608 as an aircrewAircrewAircrew are the personnel who operate an aircraft while in flight. The composition of the crew depends on the type of aircraft as well as the purpose of the flight.-Civilian:*Aviator** Pilot-in-command** First officer** Second officer** Third officer...
self-defense weapon. It is mechanically similar to the Rifle configuration, but has several external modifications made to fit into United States Air ForceUnited States Air ForceThe United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
size constraints. These include a cut-down pistol grip, an absent handguard, shortened barrel and receiver, and a top-mounted cocking handle. The Survival Rifle does not incorporate the 63A upgrades. Only one prototype was ever produced—it survives to this day.
The most recent descendant of this line is the Stoner LMG
Stoner LMG
The Stoner LMG is a light machine gun system developed by Eugene Stoner and manufactured by Knight's Armament Company . It is also known as the KAC Stoner 96 LMG to differentiate it from the earlier ArmaLite Stoner 63 LMG and Ares Stoner 86 LMG it is derived from.The Stoner LMG is billed by KAC as...
produced by Knight's Armament Company
Knight's Armament Company
Knight's Armament Company is an American firearms and firearms parts manufacturer.It is owned by C. Reed Knight and based in Titusville, Florida. KAC is best known for producing the Rail Interface System and the Rail Adapter System grips for military firearms...
, which has significant changes from the older Stoner 63.
Robinson Armament Co.
Robinson Armament Co.
Robinson Armament Co. is a firearms manufacturer founded in 1996 which is based Salt Lake City, Utah, USA. It produces and markets many different civilian and military oriented designs in the United States....
also produces the semi-automatic
Semi-automatic firearm
A semi-automatic, or self-loading firearm is a weapon which performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges remain in the weapon's feed device or magazine...
M96 Expeditionary Weapon System which, though technically different, was based on the Stoner 63 design, and thus has some of its features and configurations.
Also to note a bullpup conversion was made from AR-18 assault rifles by Enfield when developing the SA80.
Designations
The rifle, carbine, and Commando LMG variants were all given designations by the US Military. They are as follows:| US Army Designation | US Navy Designation | Description |
|---|---|---|
| XM22 | N/A | Stoner 63, Rifle configuration |
| XM22E1 | N/A | Stoner 63A, Rifle configuration |
| XM23 | N/A | Stoner 63, Carbine configuration |
| XM207 | N/A | Stoner 63, Commando configuration |
| XM207E1 | M63A1 | Stoner 63A, Commando configuration |