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Stoner 63 System

After his success with the AR 10/15/16/18 series of rifles, designer Eugene Stoner went on to develop the Stoner 63 weapons system with the Cadillac Gage company. The Stoner 63 was in many ways a natural evolution of the AR15 rifle, with a strong emphasis on modularity.

Stoner 63 configurations

The driving idea behind the Stoner was to use a single receiver for an entire family of weapons. The stocks, barrels, sights, feed assemblies, trigger assemblies and other main components were all modular and interchangeable. Some configuration changes were relatively simply, like changing between rifle and carbine – the carbine used a shorter barrel and folding buttstock. The more impressive design achievement was the ability to flip the receiver over to change from shoulder rifle to light machine gun configuration.

The rifle and carbine designs use a gas piston on top of the barrel and magazine fed from the bottom. The accommodate a belt feed, though, the belt needs to be fed from the top of the gun, which thus requires the gas piston to be on the bottom (you can see this on virtually every gas operated LMG, like the Bren and BAR families). The Stoner allow the rifle receiver to be rotated 180 degrees and mount the LMG components in this way.

Other features included a fixed vehicle mount design fired by solenoid, and tripod adapter to allow the gun to be used with the standard US machine gun tripods of the day.

The Stoner was used experimentally by special forces in Vietnam, though it was eventually declined for regular issue due to high maintenance requirements.During the procurement process, a number of modifications were requested by the military, which resulted in the development of the Stoner 63A – most significantly a change to right-hand feeding for the belt fed models, to eliminate the problem of ejected casings bouncing back into the feed port and causing malfunctions.

We have a preliminary official manuals for the Rifle, LMG, and MMG configurations of the Stoner 63/63A, as well as a sales brochure for the weapons system, a Cadillac-Gage report on the design changes from the 63 to 63A variant, and a maintenance annex to the testing reports on the 63. These are available here, as well as on the Original Manuals page in the Vault.

Stoner 63 System sales brochure (English)

Stoner 63A rifle manual (English)

Stoner 63A LMG manual (English)

Stoner 63 MMG manual (English)

Annex to Service and Troop Tests, Stoner 63 System (English)

Cadillac-Gage Engineering Change Report for Stoner 63A (English)

20 comments to Stoner 63 System

  • Hrachya Hayrapetyan

    Thanks for this collections of manuals !!! I was waiting for this post and it’s great!
    Today we talk a lot about a modular firearm to replace AR15 platform guns… Just look at this gun. This is the most modular weapon system I’ve ever seen !!! It’s simply genius ! I like Stoner 63 system !

  • Robert

    It appears that the 63A Rifle manual and the Annex are both damaged files. Otherwise, this is an excellent post!

  • Val

    Thanks for this incredible weapon information,
    I been waiting for it too long but no info available elsewhere…
    I had repaired those 2 pdf files,Annex have a better graphics manual than other one black and white color..
    i wish someone will upload Franchi LF57 smg manual anytime sooner..

  • duchamp

    interesting that the 63a has a side folding stock instead of the later underfolding one…

  • ferrariguy1000

    It is finally here! info about the Stoner 63. Thanks guys. I was wishing for info on how to change to the different types of the Stoner, but this is awesome enough for me to understand now.

  • yyy

    thank you for this post excellent information
    couldn’t find it anywhere else

  • Gunny

    Thank you for uploading the manuals. The Stoner 63A is one of the finest weapons ever designed and my favorite belt fed to shoot.

  • Jim PTK

    I worked with Gene Stoner at Cadillac Gage Company while the Stoner 63 system was being developed. As someone commented, the system was able to do many different things with very little adapting. One variant that I designed was a backpack to hold the ammunition belts that were used on the helicopter fixed weapons. Each belt held 300 rounds of ammunition and was wound in a spiral. It was designed so the crew could remove the Stoner and ammunition belts to be used if the copter was disabled. It enabled a small crew to carry a lot of firepower if they were shot down.

    There were many interesting projects during Stoner’s time at Cadillac Gage. Once, they mounted a weapon in a vice to film the firing mechanism in action. It was aimed a thick armor plate to deflect the rounds down into a bucket containing two feet of sand. When we finished, we found that every shot after being deflected 90 degrees had gone through the sand and the bottom of the bucket. They were buried in the concrete that it was sitting on.

    • Ian


      I was wondering if you had any more info on the rear sight differences between the 63 and 63A rifle. I know a lot of rifles had their parts mixed and am trying to figure out the reasoning between the 4 and 5 hole variants and if they were designed for a specific variant. Thank you.

  • Donavon

    I was one of the lucky few who got to “test” the 63A in EWAT at hunter ligget and another place. not sure if that one is still classified, but I doubt it. Outstand in light machine gun mode, belt-fed.

  • David

    Love this weapon. As a Title 2 mfg. years ago, I acquired an original transferable 63….and then years later I bought a 50 gallon drum full of demilled Stoner’s….belt fed, rifle, Bren-style lmg’s. These came out of Crane NWS. Eventually I assembled a few post-86 DS firearms. Lots of fun shooting them. I still have lots of parts.

  • Oliver Love

    Are there any photographs of the other side folding stock options?


    • David

      The side-folding hinge is a separate item that can be screwed to the standard black plastic stock. Or it has a rubber coated tube stock welded to the hinge. I have both….and it locks up guten-tight. The top cover and feed tray have to be lifted up….and the tube stock folds right up against the receiver….then the top cover and feed tray can be lowered. If I could download pics….I’d send one.

  • Thanks,

    Needed some info on Stoner’s original work


  • stoner guy

    what is a stoner 63 right hand feed LMG worth today? how marketable are they? where could parts be found?

  • Mark

    The United States Marine Corps tested the Stoner 63 from May, 1964, through basic training at Parris Island and beyond for 6 months with one platoon, 236, now known as the Stoner Platoon.
    This platoon currently holds annual reunions, having recently done it’s 50th, and will be together again in May, 2015. This platoon and it’s drill instructors worked with firing, cleaning, and developing a manual of arms for the Stoner which proved to be an excellent weapon.
    Nearly all the members of the platoon are back together lacking only a few out of touch men we can’t find. We also know of those that are on the Vietnam Memorial Wall. Semper Fi !

  • Dave

    I was issued a Stoner 63 in Vietnam. It was the best weapon I’ve ever used. Sure saved my butt on many occasions. L Co/3rd Bn/1st Marine Division Vietnam 1966-1967

  • MpowerdAPE

    Is there any truth to the rumor that the Chicago Police Department received a large order of Stoner63’s…?

  • HerrKreutz

    Hello friends of Stoner.

    I recently purchased Stoner 63A Mk.23 in airsoft version, as real steel would cost me even my pants (and nearly impossible to get it in Europe).
    Like the concept, size etc. My question is, what clothing, camouflage pattern and harness did you guys used in Vietnam?
    I would like to get the reenactment as close as possible.

    Thank you for your time.

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