.222 spl


Cartridge with measuements like a 223 Rem but has a headstamp with
"REM-UMC 222 SPL". What type of cartridge is this??


I believe these were among the first of the .223 rounds made by Remington, before the designations “.223/5.56 NATO” were finalized. Remington designed the case for Armalite by moving the shoulder forward on the .222 Remington cartridge and then shortening the neck. they called this modified case the .222 Remington Special and in 1957, made the first rounds headstamp simply REM-UMC 222. After that, in 1957 to 1958, they headstamped them REM-UMC 222 SPL. These early rounds were loaded at Remington and used a Sierra 55 grain FMJ bullet, nickel primers and a IMR4475 powder, made by Dupont.

In 1959, Remington changed the designation to “223” to avoid confusion with the .222 Remington, and with their then fairly new commercial .222 Remington Magnum cartridge.

Reference: “The History and Development of the M16 Rifle and its Cartridge” by David R. Hughes, Pages 26-27.

John Moss


As always, thanks John



A correct summary except that I believe that the cartridge specifications were developed by Armalite and Remington produced them accordingly. At least that is what the label on my boxes say. Of course it’s possible that the “specifications” only pertained to bullet weight, velocity, pressure, etc. Although I believe Stoner had already finalized the design of the rifle and so it would follow that he also had specific case dimensions in mind.



According to Dave Hughes, and what I know from when I was collecting .223 (not much - I only collected it a couple of years and decided I was biting off more than I could chew with my other fields), Stoner had picked the .222 Remington case, but ran into problems with a too-high rate of fire in his scaled down AR-3. He began work then scaling down the AR-10 into what would become the AR-15.

Remington was working on modifying the .222 Remington cartridge to increase its powder capacity and also reduce chamber pressures to lower, more acceptable limits. Certainly there was input and cooperation from Armalite during all of this, but I would have to say that it was, indeed, Remington that designed the .223 Remington case, and not Stoner. Perhaps it would be more accurate to say that Remington took the lead and designed it in cooperation with Stoner and the ArmaLite Corporation. It was Remington, though, that suggested the design of the case. I believe that Stoner had probably set the specifications as to bullet weight, and perhaps the desired velocity, but that it was not going to happen safely within the .222 Remington cartridge case as he originally envisioned.

ArmaLite may well have supplied the bullets to Remington for the initial runs of the new cartridge, as they designed the bullet that Sierra made for ArmaLite, and mention is made of Remington using the Sierra 55 grain bullet. There is no reason to think that it was not the bullet that Stoner had designed.

Certainly, the cartridge was truly a joint effort although, again, it appears that the case itself for what we know as the .223 or the 5.56 x 45mm NATO was designed by Remington.

Of course simultaneously, the Army was working with Winchester and others to produce a small caliber round to replace the 7.62 NATO, but the Chief of Staff of the Army at the time made the decision that the Army would continue with the M14 in 7.62 NATO caliber, and the Army gave up on its development of a conventional small caliber rifle. I think the SPIW and some other programs less conventional continued, hower, although that is getting into an area where I know darned little.

The whole story of the events and development leading up to the M16 and the 5.56 x 45mm NATO round are fascinating and a lot more complicated than I had thought when I started collecting the .223 round. I highly recommend the book by Dave Hughes, as well as the book “The Black Rifle” published by Collector Grade Publications in Canada, for those with a real interest in this subject. They complement each other, rather than compete for the reader’s attention. Dave’s book is heavier on the ammo than is the “Black Rifle.”



You are certainly correct that the development of the 5.56 x 45 cartridge was a tangled web. I’m not sure that anyone will ever straighten it out but our own Daniel Watters has put togethetr a very good summary.

One other thing that makes me wonder about who actually designed what was to become the final case size and shape is that Winchester, too, was working on their own SCHV rifle and cartridge and it (the E1 and E2) are almost identical to the Remington 222 Special.

Also, Remington and Springfield Armory had their own little project underway which resulted in the 222 Remington Magnum. That program was squashed by the high brass and it is still not clear as to who authorized Springfield to develop a new cartridge when their role was strictly weapons development.

Anyway John, you should not be so modest. You obviously know a LOT about this.



Thanks for the kind words Ray. Does anyone know where David Hughes’ research wound up after his death? I’ve long heard rumors that he was working on a revised or second edition.

DTIC and NTIS have a report available titled: “Report of the M16 Rifle Review Panel. Volume 5, Appendix 4. Ammunition Development Program.” It reports the history and development of the cartridge from the Army’s perspective in 1968. It is not currently available for download; only Volume 6 out of the 12 volume set is in .pdf format.



I just recalled a 1994 interview with Mike Walker that was published in Precision Shooting magazine so I dug it out to see what he said about the development of the 223 cartridge.

[i]“Remington and Winchester were both working on a .224 caliber NATO round. The cartridge was designed at Aberdeen Proving Grounds on the .222 Remington case head with a slightly longer, fatter, body and a shorter neck and came out of the development we did at Remington. But somebody at Aberdeen decided to award Winchester a contract to produce some ammunition for trial. I guess they wanted to spread business around since we did the first contract part. When Winchester got the contract, they decided they would market the cartridge as the .224 Winchester. So the manager at Bridgeport decided we would scotch that idea when he heard about it, and we brought it out as the .223 Remington first. It did scotch the idea. That round was accepted as the 5.56 NATO.”

“Actually none of us knew what we were doing then. They first brought out the 5.56 NATO in a 1 in 14 twist but the 55 grain bullet didn’t stay point on in cold weather. That is when they reduced the twist to 1 in 12 inches. Eventually, of course, they went to an even shorter twist and a heavier bullet.”[/i]

This interview was given back when Mike still had a good memory. It adds a little more confusion to the story.



Just to add to the Confusion, the first manuals (TMs) issued for the trials rifles (Armalite and others) in the .222 Special cartridge were designated “5,64mm” calibre rifles ( rendition of the Bullet diameter and groove diameter of the cartridge/barrell… Not the Militarily accepted "Bore diameter calibre ( which was soon corrected to “5,56mm”

Winchester’s .224 W cartridge was specifically developed for the Winchester Light carbine (Rifle) mechanism, a sort of Mini-14 before its time (Miniaturised Garand in Sporter style).

But that’s ancient history…soon we will see another “Remington” derived and sponsored project, the 6,8mm SPC take over from the 5,56, if there is any sense in the US Ordnance world ( I doubt it, given past activity).

The Chinese have actually beat the US on this one, getting their 5,8 cartridge out in 1987, and a matching rifle in 1995 and 97, etc.

Quality concerns have affected performance of this cartridge, but with proper development, it too could become THE modern AR cartridge of the near Future.

Anyway, even the 6,8SWPC is not really new…the cartridge case derives from the 1906 Rem Auto (Browning and Remington) and the projectile (calibre) from the M1907 Chinese Mauser… is there some sort of Hint here?

Regards, Doc AV
AV Ballistics


Good Thread. I think some of the confusion is over the use of the word “design”. Both the military services and the contractors have a heavy hand in the design of items. A simplified explaination is that the service acquisition agency lets a contract that describes something they want. Back in the time frame we are talking about it was something like a bomber that goes so far and so fast and carries so much. For a cartridge it was likely a perform specification contains things like MV, blt weight, etc. This performance spec was typically put on contract. The contractor could recommend changes to it, and from it was derived a functional spec which described how the thing would work in more detail, and eventually a physical configuration spec which physically describes what it is that the government is going to buy. I doubt the Army put out a contract for a cartridge, but rather the performance spec was for a weapon, and the cartridge was covered as part of the spec. Part of the process involves typically two design reviews where the contractor and government technical people go over first the preliminary design and then the final physical design. Usually, a lot of changes come out of both of these. The physical design must be approved by the government before production. So who designs something-it is an iterative process involving the government and the contractor.

This may be interesting (or not) but is not directly relevant to the .223 development. Stoner, as far as I know and have been told, developed the AR-15 and the 223 cartridge as a seperate effort without a government contract or direct government input. The government (the Air Force) bought both from Stoner as a Non-Developmental Item (just like they would buy a commercial item like a common laptop PC today). As a result, the government had no offical input into the design of either the gun or the cartridge.

Remember, Stoner was a Colonel who retired out of the Army weapons & ammo development process, with lots of ties back to the process. I suspect his experience shaped his thinking, in which case, he would have given a performance spec of some type to Remington and then worked with them in the detail design of the cartridge. I suspect Stoner had input on everything including the final dimensions of the case-he was the customer and based on his background he would insist that it was his final decision on what the physical design of the cartridge.

I think Mike Walker was right when he said the cartridge was designed at Aberdeen, but he meant the performance spec. My reply to Ray Meketa’s posting “GA Gustafson (5.56x45 / AR-15 pioneer) Gone” mentions that Gustafson told me that, before he left Aberdeen, he wrote a report describing what he considered the ideal small caliber infantry cartridge, and that Stoner told Gustafson that this report was the basis of the 223/5.56x45mm cartridge.

Gustafson was a key player in the Air Force buy of the AR-15 and the 223 cartridge. The gun was in operational use with the AF when the Army initiated their development process as described above which resulted in the buy of the redesigned M16. I don’t know if the Army development process in the early 1960s resulted in a revision in the design of the cartridge which was acquired initially by the AF.


Now that is an “insiders” explaination that brings us all a little closer to the real deal…thanks Lew

I always liked the cliche…'there are three sides to a story…“yours”…“mine”…and the “real one”

'sure is nice to read these threads


Lew’s explanation would square with what Dave Hughes basically reported, regarding the design of the cartridge case itself. Velocity, pressure and muzzle energy specifications can result in many different forms to the cartridge case, all attaining the same performance specifications. I have no doubt that the original performance specification was drawn up, probably also with input from Stoner, at APG. It would seem what Lew says corroborates that Remington drew up the physical case design with Stoner’s input. That is basically what Dave Hughes reported in his book. Hughes mentions that Stoner originally tried the .222 Remington case, but probably loaded to a higher velocity and pressure than Remington’s original specs for the .222 (Hughes doesn’t directly say that, but it would account for the problems he describes), as the book reports problems with a too-high rate of fire in the first prototypes that were shot with the .222-cased ammunition. By moving the shoulder forward, and then shortening the .222 neck so that the cartridge was still the same basic OAL as the .222, a larger powder chamber was created and pressures brought under control, without any need for any major redesign within the weapon or of the magazines.

While I agree completely that Stoner would have had input into most every detail of the cartridge design, including that of the case, his having the final decision on every aspect of case design would have gone only as far as the safe limits of the design arrived at. Regardless of being the customer, had his ideas for the case been unsafe, in Remington’'s opinion, I am sure they would not have accommodated him. I doubt this was the case, however, since Eugene Stoner was quite expert in such matters hmself. There was undoubtedly much mutual agreement over the fix needed to safely and efficiently achieving the required specifications.

As a couple of interesting side-notes to the subject of the early .223 rounds, the earliest form I had in my collection before I sold it had the headstamp “REM-UMC 222” with the “222” being off-center, since the letters “MAG” had been removed from the bunter. The “222 SPL” designation came after that. I also had a .223 from NORMA with “NORMA Re .222 Magnum” headstamp, and my notes indicate that it was a NORMA pre-production round.

In 1975, Burton Miller of ArmaLite Inc., Costa Mesa, California, kindly sent me a sample of the .223 with the GM bullet coated with Dukote Teflon, an experiment they tried for bore lubrication (I don’t know why, exactly). At the time, he said they only had six rounds left at the factory, that were probably accidentally retained - that is they simply didn’t finish shooting up the full box. The headstamp was “W C C 7 2” on that cartridge. He also sent a five-lobe, rose-crimped blank with the “REM-UMC 222 SPL” headstamp, marked “4350” on the side, an ArmaLite experimental blank. I don’t know the meaning of the “4350.” It was not explained. I am not sure that IMR-4350 powder would have made a good blank, so kind of doubt that’s what it refers to, although I don’t know. Doc Av might. There were a couple of other items, but I did not note them at the time as coming direct from ArmaLite. One was a dummy with the “222 SPL” headstamp with an all-blackened case, one hole in the case and one hole in the primer. That was a Remington factory dummy, but I think that was among the items sent to me. In Miller’s letter to me, he mentions that he is sending “the new steel case 6mm L.C. (cases only) along with a 105 grain bullet.” I don’t really remember that, as I would have passed it on to someone else. I suppose it was the SAW round, and that perhaps ArmaLite had expressed interest in that. I know next to nothing about that cartridge and its history - just have never had the impetus to study it.

I wish I could remember everything we talked about on a follow-up call to my request for the Dukote cartridge. I was not keeping the best of notes in those days, unfortunately.


John, I’d make a slight change in your statement

It goes back to the defination over who had final design authority. The government, and I am sure Stoner had final design authority, but it is always a negotiation. If Remington decided the design was unsafe and couldn’t get Stoner to agree to something Remington could accept, the only Remington option was to terminate their involvement, NOT to insist on their design. Had they done that then Stoner would have had to go to someone else for the design. It is not unusual for this to happen in military or commercial acquisition programs. It has happened over safety, but more often over performance, technical risk or cost. Where a company is designing for a set of customers, like in a laptop PC, they write their own requirement (performance spec) and make the development decisions themselves, but when they are doing the development for someone else, particularly the government, the customer makes the final decision to accept the design. In this case, I’m sure the final decision on safety was Stoner’s because he knew a lot more about the capabilities of his weapon than Remington did. When two people agree on an aspect of design it can be hard to decide who made the decision, but there is no question in my mind who had the authority to provide final approval of the design. That was Stoner. If Remington wanted one shoulder angle on the case and Stoner another, then Remington’s options were to convince Stoner, terminate their involvement in the development or find a compromise they could agree with Stoner on!!! They never had the option to direct how to chamber the AR-15 over Stoner’s objections!


FWIW: Everything I’ve seen on Stoner indicates that he was an enlisted Marine during WW2 and left for civilian life after the war. ArmaLite hired him after one of its principles happened across him at a rifle range shooting an aluminum receiver, semi-auto .308 rifle of his own design. Stoner was offered a job on the spot, and the rifle became the AR-3.

The former Colonel fresh out of Army Ordnance was probably Mel Johnson, who served as a consultant to ArmaLite.


For you headstamp hunters , here are the 5 basic headstamps in the series. They can sometimes be missed by a collector not familiar with them, so keep your eyes open.

Sorry about the upside-down ones. It was windy in my garage and they kept rollong around.


REM UMC 222 with “MAG” ground off the bunter



Winchester E2

224 Springfield


As for the similarity between the Remington and Winchester cases, it has been my understanding that Stoner approached Winchester first to produce an extended version of the .222 Remington. They turned him down, so Stoner went on to Remington. The .224E2 Winchester and .222 Special share the same chamber dimensions simply because CONARC insisted that they agree to a common chamber. CONARC wanted to be able to use the same ammunition between the AR-15 and Winchester LMR during their testing. Unfortunately, the LMR was hamstrung by its design around the original, shorter .224E1 Win cartridge. Winchester didn’t want to redesign the rifle for the overall cartridge length of the .222 Special, so the .224E2 Win had the same short OAL as the .224E1 even though the new case was longer. As a result, the initial CONARC testing of the LMR and AR-15 had to be done using the .224E2 Win.

The USAF didn’t enter the picture until after CONARC had moved on to other projects and Winchester had dropped development of the LMR.


A lot of the problems might have been avoided if Remington had just spilled the beans earlier on their development of the .224 Springfield. Of course, this probably would have caused problems with Army Ordnance. However, the Army didn’t seem to mind when Remington later commercialized the .224 Springfield as the .222 Remington Magnum.


Lew - I agree with you. I only used an example to show that the customer isn’t always right - that is, the customer doesn’t always have the final decision. A decision by a company to withdraw from the project is just as final for that company as a decision to approve a design. Simply making a point. In fact, I expressed the doubt that this would have happened between Stoner and Remington because Gene Stoner was so knowledgeable. I doubt that Stoner would have argued a safety point with Remington anyway, after his initials experiments using the .222 case were pretty much failures. He was too smart for that as well. We have no basic disagreement here!



Reference your posting:

[quote]FWIW: Everything I’ve seen on Stoner indicates that he was an enlisted Marine during WW2 and left for civilian life after the war. ArmaLite hired him after one of its principles happened across him at a rifle range shooting an aluminum receiver, semi-auto .308 rifle of his own design. Stoner was offered a job on the spot, and the rifle became the AR-3.

The former Colonel fresh out of Army Ordnance was probably Mel Johnson, who served as a consultant to ArmaLite.[/quote]

I am out of my depth here. All I know is what I thought Gustafson told me. I know Gustafson was a GM15 civilian at Aberdeen in a firearms unit, and I thought he told me his boss was Gene Stoner and I thought he said he was a Colonel, but that may have been men since s GM15 would normally be the deputy to a Colonel. The conversation was a long time ago. I went to the New York Times web page and it said the following:

"Eugene Morrison Stoner was born in Gasport, Ind., on Nov. 22, 1922, the only child of Lloyd and Britannia Morrison Stoner. He moved to Long Beach, Calif., where he graduated from a technical high school. After the Depression there was not enough money in the family for him to attend college, and he went to work in 1939 for Vega Aircraft, which later became part of the Lockheed Corporation. He served in the Marine Corps in World War II in the South Pacific and northern China. After the war, he was employed by the Fairchild Engine and Airplane Corporation.

Hearing about his work, Army experts sought out Mr. Stoner in the mid-1950’s to help develop automatic rifles using smaller, faster bullets. Later, in the early 1960’s he invented what came to be known as the Stoner 63, an automatic weapon using interchangeable parts that could be converted from a light rifle into a rapid-firing gun to conserve ammunition. "

Which makes it clear he was not an Army Officer. I will say the article also said “His M-16 has been standard issue for the United States armed forces since 1963,” which is untrue since by late 1966 the only major units in Vietnam using the M16 that I saw were the airborn and most of the ones I saw were carrying M14s. As an AF guy I had an AR-15.

The story Gustafson told me is at the thread I referenced earlier at

iaaforum.org/forum2/viewtopic.ph … hlight=223

All I can say is this is the way i recorded what Gustafson told me. I also know from others involved like Dale Davis who headed gun development in the Armament lab at Eglin for many years is that they confirmed the highpoints of the Gustafson story. All are dead now so I can’t sort out what I thought I heard. Sorry for any misinformation I may have created!



I think that neither Remington nor Springfield Armory were in a postion to say anything because they both probably got their butt kicked by Army brass for exceeding their authority, maybe not literally but figuratively to be sure. Not only were they working on a new small-caliber cartridge design, which was outside the mission of Springfield, but they ran the risk of compromising the development of the T65 which was having a hard enough time being accepted by NATO as it was.

But, you’re right. Had the 224 Springfield been advanced in the beginning we probably would have never seen the 223 and all the confusion surrounding it’s development.