The 5.56 X 45mm “Timeline” – 1963

A Chronology of Development by Daniel E. Watters



Build a Better Mouse Gun, and the World Will Beat a Path to Your Door.” ArmaLite project engineer Arthur Miller scales down Gene Stoner’s 7.62mm NATO AR-16 design into the 5.56mm AR-18. Enticed by Stoner to join him at Cadillac Gage, L. James Sullivan and Robert Fremont scale down the 7.62mm NATO Stoner 62 into the 5.56mm Stoner 63. Beretta and SIG join forces for a 5.56mm rifle project. At Heckler & Koch, Tilo Möller begins development of a scaled down 7.62mm NATO G3 into the 5.56mm HK 33.

Remington commercially introduces the .221 Remington Fireball, a shortened .222 Remington, along with the XP-100 bolt-action pistol.

Weatherby commercially introduces the .224 Weatherby Magnum. While supposedly under development for nearly a decade, the cartridge is roughly an improved .219 Zipper with a belt and Weatherby’s radiused shoulder contour.

Valtion Patruunatehdas of Lapua, Finland begins loading the Russian 5.6x39mm Running Deer cartridge. Later, the cartridge and case are commercially manufactured by Sako as the .220 Russian.

The Army’s Deputy Chief of Staff for Military Operations (DCSOPS) LTG Theodore W. Parker publishes the study “Rifle Evaluation: A Comparative Evaluation of the U.S. Army Rifle M14, the Armalite AR-15, and the Soviet Rifle AK-47.” The study recommends “only the M14 is acceptable for general use in the U.S. Army.” The study states that the AR-15 is less reliable, has poor pointing and night firing characteristics, has only “marginally satisfactory” penetration, and its adoption would violate NATO standardization agreements. Three alternative courses of action are proposed:

  1. Continue M14 production until a radically improved weapon can be procured, such as the SPIW or its equivalent;
  2. Terminate M14 production at the end of FY 1963 procurement. Rapidly procure a militarized AR-15 to complete inventory objectives. Reorient the research and development program to provide a weapon meeting or exceeding the SPIW‘s characteristics in the future; or
  3. Continue M14 production. Procure a militarized AR-15 in FY 1964 to equip air assault, airborne, and Special Forces units. Continue SPIW development to support procurement in FY 1967.

Not surprisingly, LTG Parker recommends the first course of action, with development of the SPIW projected for an initial procurement in FY 1965.

In a memo to Secretary Vance titled “Comparative Evaluation of the M14, AR-15, and Soviet AK-47 Rifles,” General Wheeler reports “The AR-15 is not now acceptable for the Army for universal use.” Supporting arguments included that adoption of the .223 Remington cartridge would violate NATO standardization, that the M14 was superior at ranges over 400m, and that the AR-15 design was not completely debugged or reliable. In the trials, the AR-15 suffered a malfunction rate eight times higher than that of the control M14 rifles. In addition, testing at Aberdeen and Edgewood Arsenal could not duplicate the terminal results reported by ARPA‘s Project AGILE.

General Wheeler recommends:

  1. In FY 1964, procure between 50,000 and 100,000 AR-15 rifles and use them to equip Air Assault, Special Forces, and Airborne units;
  2. In FY 1964, procure a sufficient number of the M14(M) rifles to provide an automatic rifle capability to all infantry squads armed with the M14 rifle;
  3. Reduce the FY 1964 M14 program by a number sufficient to accommodate recommendations 1 and 2 above; and
  4. Continue the current SPIW program and undertake expedited improvement of the AR-15 to determine which of these weapons will best meet the requirement for a follow-on rifle.

Some questionable decisions and outright skullduggery surface in the Inspector General’s investigation. For instance, the AR-15 was judged against M1 rifle-era requirements such as aimed fire out to 800m. The AR-15 rifles were required to fire full automatic, while the M14 rifles were allowed to remain on semi-auto. For comparison testing, the Infantry Board even brought out prototype match rifles and squad automatic versions of the M14 such as the M14(USAIB) (AKA: the M14E2 or M14A1). A representative from the Office of the Chief of Research and Development telephoned TECOM suggesting that Aberdeen’s D&PS use a specific form of rain test to induce failures in the AR-15. The M14 was not subjected to the same test. Aberdeen’s BRL switched out a M14 being used for accuracy testing when it showed signs of inaccuracy. Accusations were also made of the use of handpicked lots of match grade ammunition for M14 accuracy testing. Negative aspects of the M14’s testing were downplayed or even omitted from reports, while the AR-15 was consistently portrayed in a negative fashion even when the test results indicated otherwise. All attendees of the October 1962 planning conference were interrogated. They denied under oath that they had planned to fix the rifle evaluations against the AR-15. The USAIB representative, an Army Colonel, explained that his infamous memorandum was not what he meant to express, and blamed its wording on administrative error. Admittedly, some of the AR-15’s problems in testing were real, the result of rushed production of the rifles and their ammunition for the rifle trials. The biggest problem experienced was primers blown out of the case upon firing. (Robert Macdonald was so upset that he sent individual letters to Colt and Remington, accusing both companies of sabotaging the tests.)

In a report to the OSD, Secretary Vance recommends the following: 1) Procure enough rifles converted to the M14(USAIB) standard for issue as automatic rifles to all infantry squads; 2) Procure 50,000-100,000 AR-15 for issue to Air Assault, Airborne, and Special Forces units; 3) Production of standard M14 rifles is to be reduced; and 4) The SPIW program will be scheduled to provide a “follow-on” replacement for the M14 by the end of FY 1965. In response, McNamara announces the cancellation of M14 production once FY 1963 contracts are completed.

The Department of Defense also accepts the USAF‘s plan to procure a total of 80,000 AR-15 rifles during a five-year period.

The ODCSLOG submits a staff study of the Army’s AR-15 rifle requirements. Procurement and distribution is proposed as follows:

Purpose Air Assault Special Forces Airborne Total
Initial Issue 13,000 6,665 34,352 54,017
Maintenance Float 630 333 1,718 2,701
Combat Support (6 months) 5,070 2,598 13,386 21,054
Pipeline (2 months) 1,690 366 4,462 7,018
Total 20,410 10,462 53,913 84,790

In the end, the Army proposes a “one-time” purchase of 85,000 AR-15 rifles. It is intended as a stopgap measure until the SPIW is ready for fielding.

CDCRE-E sends a letter to LTG Besson titled “AR-15 Rifle Deficiencies.”

The USAF type-classifies the .223 Remington under the designation “Cartridge, 5.64 Millimeter Ball MLU-26/P.” The military specifications for the ammunition is published as MIL-C-9963. The USAF also releases the report “Exterior Ballistics of the AR-15 Rifle.” The results of cold chamber testing at Eglin Air Force Base indicate that the ammunition cannot meet accuracy requirements in subzero temperatures. A change in the rate of twist from 1-in-14″ to 1-in-12″ is noted as solving the problem.

A meeting is held at Lake City Army Ammunition Plant between Army and USAF representatives. The purpose of this meeting is to develop practical drawings and specifications based on the previous experience of the USAF with Remington cartridges. The USAF points out that the performance of the Remington cartridges have not been satisfactory because of four principal deficiencies: keyholing, stripping of the bullet jacket, packaging, and a light powder charge. The MUCOM representative stresses the importance of having a military specification for the rifle, since any variation in the design of the rifle could require a change in design of the ammunition.

The USAF receives the final AR-15 of its original 8,500 rifle order.

Aberdeen’s Human Engineering Laboratory (HEL) releases the report “Summary of Studies Conducted with the AR-15.” The report contains a summary of firings conducted with the AR-15 using several muzzle brake deflectors and other means to reduce automatic fire dispersion.

The HEL also publishes “Measurement of Peak Sound-Pressure Levels Developed by AR-15 and M14 Rifle Bullets in Flight.”

WECOM begins contract negotiations for prototype SPIW construction.

Springfield submits Request for Proposals to various facilities for support in the design, development, and fabrication of a large capacity magazine, a grenade launcher, and a muzzle device for Springfield’s own SPIW candidate. After receiving and evaluating the proposals, Springfield requests the award of contracts. However, the development of the muzzle device is cancelled.

WECOM notifies Springfield that the accelerated program for the SPIW has been approved. Springfield begins major retrofitting of parts to its prototype, and initiates the fabrication of four test weapons.

USMC Commandant General David M. Shoup convenes a board at the Marine Corps Landing Force Development Center to conduct comparative evaluation of the AR-15. BG Lewis W. Walt is appointed board chairman. The board’s findings are later evaluated by an informal board of officers at HQMC. They conclude that:

  1. The M14 and AR-15 are essentially equal and adequate with respect to training reliability, and combat effectiveness. However, the AR-15 is easier to handle, requires less mechanical training time, and is predominately lower in system weight. As such, the AR-15 would be a more effective combat rifle for the USMC.
  2. However, there is no comparable .223 machinegun to replace the M60.
  3. Until a .223 machinegun can be developed, no .223 rifle should be adopted by the USMC.

In a memo titled “Rifle Procurement Program,” the JCS recommends procurement of the AR-15. A day later, in another memo of the same title, McNamara officially approves the procurement of the AR-15.

LTG Besson writes MG Lynde directing WECOM and MUCOM to take necessary action to identify problems in weapon and ammunition compatibility, and to begin corrective action. Specific problems cited in the letter are:

  • Raised and uneven primers;
  • Inaccurate primer staking;
  • Bullets inadequately crimped to the cartridge case;
  • Excessive chamber pressures;
  • Sluggish functioning of weapons possibly due to wrong pressure curve;
  • Different cartridge and chamber dimensions.

The first firing model of the Stoner 63 is fabricated.

Johnson Guns, Inc. commercially introduces the MMJ 5.7mm Spitfire conversion for M1 Carbines.

Deciding to limit the SPIW competition to four candidates, WECOM awards SPIW development contracts to recently displaced M14 contractors H&R and Olin-Winchester. AAI and Springfield Armory have already begun developing their own SPIW.

WECOM requests a concept and feasibility study of a conventional configuration for the Springfield SPIW mechanism, currently in bullpup form. The study determines that it is not feasible to make any major design changes. However, a compromise approach is found which does not alter the basic mechanism’s functioning parts. By means of a conversion kit, the compromise design can be assembled to have a bullpup configuration or a conventional configuration. (The latter is referred to in drawings as the USAIB configuration.)

Winchester completes its contact for an improved “soft recoil” prototype mechanism. By this point, Winchester has overcome its functional difficulties.

In a memo titled “Rifles,” Army CRD LTG Dwight E. Beach notes a conversion with General Wheeler in which Wheeler expresses skepticism about the SPIW and states that “Perhaps the AR-15 will be the Infantry weapon of the future.”

LTG Besson establishes the “Office of Project Manager for AR-15 Rifle Activities,” appointing LTC Harold W. Yount the Project Manager. The goal is to facilitate cooperation between the services in developing military specifications. However, the very same day in a meeting at the office of the Assistant Secretary of the Army (Installations & Logistics) – ASA(I&L) Paul R. Ignatius, Army and USAF representatives clash over proposed changes to the rifle, including a change in rifling twist (favored by the USAF) and the introduction of a bolt closure device (favored by the Army).

Days later, OASA(I&L) sends the memo “Changes in the AR-15 Rifle.”

The Inspector General’s findings are released as a six volume report titled: “IG Rifle Evaluation.”

McNamara sends a memorandum to Secretary Vance titled “AR-15 Ammunition and Rifle,” designating the Department of the Army as the procurement agency for all DOD users of the AR-15 rifle and ammunition beginning in FY 1964. The military services are to agree upon a joint set of requirements for the rifle and ammunition. These items are to be produced with minimum delay and modifications. Modifications are to be made only if absolutely necessary.

LTC Yount directs that 600,000 cartridges be procured immediately to support the Army’s existing 338 AR-15 rifles.

The JCS concur with CINCPAC Admiral Felt’s decision to deny MACV‘s request for AR-15. Oddly, McNamara approves the JCS‘ recommendation.

Frankford Arsenal is assigned oversight of the procurement of .223 Remington ammunition. William C. Davis is assigned as “AR-15 Project Director” and is directed to prepare a technical data package.

Springfield Armory is requested to perform a modified weapons performance test on six AR-15 Rifles to evaluate and/or confirm problems reported during the previous Army-wide evaluation tests. The new tests are meant to determine the degree of seriousness of the reported problems and to recommend whether redesign or product improvement is necessary for the parts reported deficient. After Springfield testing confirms the earlier reported issues, LTC Yount orders Springfield to conduct “best effort” studies of the magazine and feeding system, development of an improved muzzle compensator, feasibility studies of a bolt closure device utilizing the charging handle, and a grenade launcher attachment. All the product improvements are to be accomplished, if possible, without a major redesign of the weapon or appreciable increase in the cost of the major item. In addition, an ammunition-chamber compatibility study in conjunction with Frankford Arsenal is to be conducted.

The report “Engineering Test on Interchangeability of Rifles, Caliber .223, AR-15” is published.

At the end of the month, MG Lynde establishes the “Technical Coordinating Committee” (TCC). The TCC will ultimately be comprised of LTC Yount, members of each service branch, William C. Davis from Frankford Arsenal, Charles F. Packard from Springfield Armory, and representatives from the OSD: the Deputy Assistant Secretary for Weapons Acquisition and Industrial Readiness James N. Davis and Frank J. Vee, a program analyst from the Directorate of Major Items, Materiel, Installations & Logistics. While LTC Yount is the titular chair of the committee, the OSD representatives have veto power over any decision made by the TCC. Within the next few months, over 130 changes are proposed for the rifle and ammunition. One of Army recommendations vetoed by the OSD is for chrome plating of the bore and chamber.

WECOM Deputy Commanding General BG Roland B. Anderson sends memo to USAF and USMC titled “Appointment of AR-15 Technical Committee.”

General Wheeler orders a review of the Army’s entire Arsenal system. The report ultimately concludes that only five of the Army’s ten arsenals be retained in their existing capacity. The reports recommends that Springfield Armory be among those studied for future closure.

The US Army Arctic Test Board reports on testing of the AR-15.

Springfield Armory publishes “Engineering Evaluation of the AR-15 Rifle.”

The USMC publishes “Comparative Evaluation of M14 Rifle and AR-15 Rifle.”

ARPA orders 25 Stoner 63 in various configurations. The contract will later be modified to add six fixed machine guns for the USAF for use in conducting pod-mounted tests for aircraft armament applications, and five complete systems, of which three go to the US Army and two to the USMC.

Gene Stoner files a patent application for the design used in the Stoner 62 and the Stoner 63.

Winchester requests that all government-furnished materiel, including the test fixture fabricated under the improved “soft recoil” prototype mechanism contract, be transferred to its new SPIW contract. WECOM approves the transfer.

Secretary Vance submits a memorandum titled “Standardization and Procurement of the AR-15 Rifle” to McNamara outlining the Army’s plans for the AR-15 and ammunition. The USAF will be allowed to complete their FY 1963 procurement of 19,000 rifles independently of the Army. The order for FY 1964 is projected as 85,000 rifles for the Army and 19,000 for the USAF. FY 1965 procurement will be limited to 33,500 rifles to complete the USAF‘s previously established requirement for 80,000 AR-15. MACV‘s request for 20,000 rifles is again ignored. Vance also states that relative costs and benefits of a sole-source contract versus competitive procurement have been considered. Sole-sourcing the contract to Colt is believed to offer lower cost, earlier production and delivery, and fewer problems with administrative, legal, and employment issues. Vance further outlines some of the proposed changes to the AR-15 design discussed so far: inclusion of a manual bolt closure device, redesign of the magazine, and modification of the chamber throat to ease extraction. These changes are considered to be interrelated and inseparable. Also proposed are a redesign of the sight protectors’ angle to improve instinctive aiming characteristics during night-firing, determination of the proper rifling twist to improve the stability of the projectile, and sorting out the dimensional incompatibility of the respective chamber and ammunition dimensions. As for the latter, it is proposed that the chamber be modified instead of the ammunition. If the changes in the chamber result in degradation of ammunition ballistics, only then will consideration be given to modifying the ammunition. Ammunition will be procured competitively from commercial sources.

The USAF signs a contract for another 19,000 AR-15.

It is discovered that IMR 4475 cannot reliably achieve the quoted muzzle velocity of 3,300 fps within the accepted maximum chamber pressure specs. At the same time, Olin-Winchester is proposing a new cartridge, the .224E5. The .224E5 and its predecessor, the .224E4, are both based on the .25 Remington case, shortened to fit within the same action length as the .223 Remington. However, the .224E5 possesses a rebated rim so that existing .223 Remington bolt faces need not be altered. (Oddly enough, these cartridges bear more than a passing similarity to the .219 Donaldson Wasp, albeit without a rim.)

USAF and USMC testing of the AR-15 indicate a “slam-fire” problem. The issue is originally blamed on high primers, but this is quickly dismissed as the cause.

At Frankford Arsenal, William C. Davis issues “First Memo Report on AR-15 Rifle-Ammunition Systems: Investigation of Firing Pin Energy and Primer Sensitivity.” The kinetic energy of the existing AR-15 firing pin is found to range from 4 to 14 inch-ounces when the bolt closes. While Frankford does not currently have equipment to determine the sensitivity limits of .223 primers, they have been told by Remington that it should be comparable to military .30 Carbine primers. Primers for military .30 Carbine cartridges have “None Fire/All Fire” tolerances of 6 to 36 inch-ounces. Davis recommends that the None Fire limit for .223 ammunition should exceed 15 inch-ounces.

Aberdeen’s D&PS releases the report “Evaluation Test of the Rate of Rifling Twist in Rifle, Caliber .223, AR-15.”

BG Anderson sends memo to US Navy titled “Appointment of AR-15 Technical Committee.”

Gene Stoner demonstrates the Stoner 63 to BG Lewis W. Walt, Director of the Marine Corps Landing Force Development Center.

Gene Stoner receives US Patent #3,087,270 titled “Ammunition Magazine with a Coil Spring.”

The BRL submits “Effect of Nose Shape on Incapacitation Probabilities for Caliber .14 Bullets.”

Springfield completes its first two SPIW test weapons for in-house development work.

The BRL also publishes “A Provisional Effectiveness Evaluation of Fléchette-Firing Machine Guns Mounted on Rotary Wing Aircraft.”

MUCOM sends the letter “Production of 5.64 mm (caliber .223) Ball Ammunition for the AR-15 Rifle.”

Late in the month, the ammunition TDP becomes available to the USAF.

Gene Stoner receives US Patent #3,090,150 titled “Hand Guard Construction.”

Plans are set forth to graft a SPIW-type 40x46mm grenade launcher onto the AR-15 rifle. However, this effort bogs down due to inadequate funding.

Aberdeen’s D&PS publishes “Feasibility Test of a 40mm Grenade Launcher on the AR-15 Rifle.”

H&R releases its final report for Phase 1 of the SPIW program.

Springfield completes four additional SPIW test weapons. Two of these are intended for use by contractors, while the others are reserved for development work.

On behalf of the US Army, Frederick Reed files a patent application for a mechanism with two magazines side-by-side which will switch feed to the second magazine once the first magazine runs empty. Reed also files an application for a mechanism which uses a combination of belt feed and magazine feed.

McNamara sends a memo to Secretary Vance titled “Action on Rifle Production Base Plan.” McNamara complains of the lack of progress by the TCC, which are delaying rifle and ammunition production. He suggests that most of the modifications are not essential, and that Colt and Gene Stoner be consulted before any future changes are acted upon. For example, the OSD alleges that the slam-fire issue is mainly the result of improper handling, such as singly loading a round into the chamber without the magazine. Thus, no further consideration to primer sensitivity limits or firing pin modifications is warranted.

A meeting is held at Hill AFB to implement procedures for the transfer of USAF technical data to Frankford Arsenal for “5.64mm” ammunition.

The US Army completes the initial Technical Data Package (TDP) for 5.56mm ammunition. The TDP is based on commercial ballistics requirements with a slight amendment based on further review of commercial manufacturing experience.

At Frankford, William C. Davis files the report “Second Memo Report on AR-15 Rifle-Ammunition System: Investigation of Test-Weapon Chamber Configuration.” It is found that Colt’s chamber tolerances do not mesh with Remington’s dimensional specifications for the cartridge. Another report, “Third Memo Report on AR-15 Rifle-Ammunition System: Investigation of Bullet Configuration,” indicates that Remington is no longer using the original 7-caliber ogive bullet design. Instead, they have switched to a less aerodynamic 5.5-caliber ogive design. The replacement design is claimed to be easier for the company to mass-produce. Davis points out that if the original projectile design were reintroduced, the pressure level of the ammunition could be reduced 3,000 to 4,000psi by relaxing the required muzzle velocity to 3,150 fps. However, despite the reduction in initial velocity, the superior ballistic shape of the original bullet would still result in higher impact velocities at all ranges beyond 100 yards than with Remington’s inferior projectile design. However, further research will need to be completed to determine the proper rate of twist for the Sierra bullet, as well as examine its terminal ballistics. Frankford Arsenal also releases “Fourth Memo Report on AR-15 Rifle-Ammunition System: Investigation of Gas-Port Pressures in .223 Ammunition” Frankford Arsenal has designed a gauge to measure gas port pressure, and has begun taking measurements. However, engineers admit that there is no knowledge of the desirable range for gas port pressure. Gas port pressures with commercial ammunition appear to be around 15,000 psi; thus, the specification limits are set at 15,000 +/- 2,000 psi. (The tolerances are based on those used for 7.62mm NATO ammunition.)

At a subsequent meeting of the TCC, William C. Davis presents his discovery regarding the switch in bullets and its implications. The BRL also reports on its research regarding the stability and lethality of the Remington bullet design in barrels using the 1 in 14″ and 1 in 12″ rifling twists. LTC Yount asks the BRL to include the Sierra bullet in its future studies. Colt informs the TCC that a major redesign of the AR-15 will be required to implement modifications to prevent slam-fires.

Springfield completes samples of one of two AR-15 bolt closure device designs being fabricated. This pair had been chosen out of seven different concepts suggested.

After studying several independent flash suppressor and muzzle brake designs, Springfield completes design work on two combination flash suppressor/muzzle brake designs for the AR-15.

LTC Yount forwards the requirement for a chamber brush that was identified by the USAF Marksmanship Unit, Lackland AFB and by Gene Stoner. This information is passed along to HQ AMC and HQ CDC.

Richard Colby files a patent application for the front-to-back tandem magazine of Springfield Armory’s 1st Gen. SPIW.

Springfield awards separate contracts for development of their SPIW high capacity magazine and grenade launcher.

TCC progress breaks down, as the US Army demands a bolt closure device. The USAF strongly objects, while the US Navy and USMC consider it “non-essential” but are willing to accept it. Colt and Springfield Armory submit various prototypes. Gene Stoner prefers Springfield’s first prototype, as it would only add two parts to the design. The Army prefers Colt second design devised by Colt’s Foster E. Sturtevant.

Springfield revisits the issue of conventional versus bullpup configurations for its SPIW candidate, along with a new issue of the magazine arrangement: “tandem” stacking versus “four to two row” stacking. Examples of both conventional and bullpup SPIW are sent to the Human Engineering Laboratory at Aberdeen for testing. As for the magazine, tandem stacking is selected. In addition to the activity related to the configuration tests, the cyclic rate of the SPIW is increased by approximately 50 percent. The test firing of prototypes is plagued by failures-to-eject, misfires, overheating, and excessive muzzle blast. The need to eliminate these problems results in the decision that additional development is required and that the Armory will not be able to make delivery of three SPIW to WECOM HQ in November. Springfield’s Model Shop begins fabrication of three SPIW, while the Operations Division is responsible for the fabrication of seven others. Each is expected to complete fabrication by the end of the calendar year.

USAF lets a contract to Remington for 19 million rounds of ammunition.

In a memo titled “Procurement AR-15,” WECOM Deputy Commanding General BG Roland B. Anderson directs LTC Yount to formulate plans for the FY 1964 procurement of 85,000 AR-15 for the US Army. Yount is to include two items in the Army’s negotiations with Colt for the AR-15. First, they should attempt to acquire the production rights and the technical data package (TDP) for the rifle. Second, they should negotiate out Fairchild’s 15 percent royalty on spare parts. Representatives of the Project Manager’s office, Springfield Armory, and WECOM meet to develop the plan. Yount subsequently begins briefing higher authorities.

The “AR-15 Conference” is held at Springfield Armory. A task group of representatives from WECOM, Springfield Armory, the USAF, the US Navy, and the USMC develop performance specifications based on conventional type rifle requirements such as headspace, proof testing, firing pin indent, trigger pull, etc. These are published as Springfield Armory Purchase Description (SAPD) 253: “Acceptance Testing Specification for Rifle, AR-15.” Malfunctions and unserviceable parts permitted during the reliability test outlined in SAPD 253 are generally the same as those specified in the USAF‘s contract AF-33-(675)-10871. LTC Yount provides guidelines (which he received from Secretary McNamara) that final acceptance testing for the AR-15 Rifle cannot be more stringent than those required for the M14 Rifle.

Secretary Vance informs McNamara that “a modification of the AR-15 rifle (the bolt closure device) is absolutely essential to improve its reliability to an acceptable level in accordance with Army combat requirements.”

In a memo titled “Action on AR-15 Rifle Modifications,” Deputy Secretary of Defense Gilpatric issues a directive to the TCC to speed up the procurement of the AR-15. Quality control, parts interchangeability, and acceptance standards are to be relaxed as necessary. Gilpatrick also directs that the OASD(I&L) will take action on any requests made by the services or TCC if it required OSD attention.

McNamara signs off on the change of rifling twist from 1-in-14″ to 1-in-12″.

LTC Yount sends MUCOM the letter “Procurement Program, 5.56mm Ammunition for AR-15 Rifles.”

The HEL publishes “Ability of Shooters to Gauge Two-Round Bursts From the AR-15 Rifle.”

McNamara and Secretary Vance visit Fort Benning and witness a demonstration of SPIW prototypes. McNamara expresses the hope that 1,000 SPIW can be procured and sent to South Vietnam for testing. McNamara’s escorts talk him out of the idea on the grounds that a large procurement of any specific prototype model would effectively prejudice the SPIW competition.

WECOM releases a Request for Quotation (RFQ) for the production and delivery of the AR-15 rifle. Included in the RFQ is a provision to obtain a complete TDP for the rifle along with manufacturing rights for second-source procurement. This will also eliminate the 15 percent royalty paid for spare parts. In addition, quotes are requested for repair parts, the M3 Bipod, Bipod Case, M7 Bayonet, and the Cleaning Brush and Pin Remover Tool.

Frankford personnel submit study to TCC regarding primer sensitivity level versus risk of slam-fires:

None Fire – All Fire limits

Risk of Slam-Fire
16-64 in-oz 1 In 10 million
12-60 in-oz (Current sensitivity limit for 7.62mm NATO) 1 in 160
12-48 in-oz 1 in 6,400
14-56 in-oz 1 in 11,000


The TCC formally approves the change in the AR-15’s rate of twist. They also approve the ammunition specification. The TCC agrees to primer sensitivity limits of a None Fire limit of 12 inch-ounces to an All Fire limit of 48 inch-ounces. The Army’s ACSFOR LTG Ben Harrell does not concur with the latter decision.

Lackland AFB notes four lots of Remington ammunition which have given accidental firing. The rates of accidental discharge range from 1 in 740 to 1 in 6,000.

LTC Yount issues program authority to MUCOM for the procurement of 1 million rounds of 5.56mm ball ammunition at a program cost of $75,000. This is a Specification Verification Quantity. A week later, program authority is granted for the procurement of an additional 27 million rounds.

Cooper-Macdonald enters into an additional agreement with Colt. Colt formally acknowledges that Cooper-Macdonald: 1) was instrumental in bringing about the Colt-Fairchild agreements of 1959 and 1961, and 2) performed a valuable service by promoting the use of the AR-15 by the US armed forces and in developing a market for it. For bringing about the Colt-Fairchild agreements, Colt is to pay Cooper-Macdonald one percent of the selling price of any AR-15 rifles, parts, and/or accessories produced by Colt or any sub-licensee. This retroactively stretches back from January 7, 1959 until some point in the future when US Patent #2,951,424 expires, including renewals of the patent. However, this is to last no later than January 6, 1979. If Colt sells a sublicense related to the AR-15, in lieu of the the previous payment plan, Cooper-Macdonald may receive 7.5 percent of any payments Colt receives from the sublicensee except for royalties paid as a percentage of the selling price for the rifles, parts, and/or accessories. Colt will continue to pay Cooper-Macdonald one percent of the sublicensee’s selling price for its rifles, parts, and/or accessories. In consideration of Cooper-Macdonald’s service in promoting the rifle and developing markets, Colt is also to pay Cooper-Macdonald $250,000 in 24 installments through December 1, 1964.

The USAIB publishes “Product Improvement Test of Armalite AR-15 Rifle (Test of Bolt Assist Device).”

US Army type-classifies the AR-15 under the designation XM16E1. It is considered a “limited standard” weapon.

On request from Colt and the Military Assistance Group (MAG), Robert Macdonald demonstrates the AR-15 in Brazil.

The Office of the Assistant Chief of Staff for Force Development (OACSFOR) sends a memo to NcNamara titled “Discussion of Alternatives Open to the Army in Regard to the AR-15 Rifle.” It recommends that the AR-15 be rejected “as an unsatisfactory weapon for Army procurement and use” based on the lack of a bolt closure device and the risk of slam-fires.

“Cartridge, 5.56mm Ball, M193” is officially type-classified. Pushed by OSD over the objections of the TCC, it specifies the Remington-designed projectile, a muzzle velocity of 3,250 fps, IMR 4475 powder, and the existing average 52,000psi pressure limit. Remington, Olin, and Federal Cartridge all refuse to offer bids. Olin objects to certain specifications on cartridge case wall thickness and to the specifications of IMR 4475 propellant. Remington objects to the same case specifications and recommends that the prescribed maximum mean chamber pressure be increased from 52,000psi to 53,000psi. Federal Cartridge expresses the view that the maximum mean chamber pressure should be
raised to 54,000psi.

Remington and Olin-Winchester representatives meet at Frankford Arsenal to discuss possible relaxation of primer sensitivity limits. They are reluctant to accept any limits other than 12-60 in-oz. Frankford indicates that this is unacceptable. Remington counters that a 12-48 in-oz limit will result in rejection of 50 percent of the primers. Olin-Winchester’s predictions are far worse, estimating that 2 out of 3 primer production lots will be rejected. This is later amended to estimate rejection of 90 percent of the primers.

Program authority is granted for the procurement of an additional 104 million rounds.

Frankford Arsenal sends a letter titled “Engineering Program for 5.56mm (AR-15) Ammunition.”

The Army Staff informs LTC Yount that the primer sensitivity limits contained in the ammunition specifications cannot be accepted because of the risk of inadvertent fire. The Army Staff prefers primer sensitivity limits of 16 to 64 inch-ounces. LTG Besson states that the only practical solution is to modify the weapon. Consequently, Colt develops and submits for test two modifications of the firing pin. These are a linear spring device and a cam pin friction device to reduce firing pin energy on bolt closure.

Both the USAF and USMC submit position papers on the bolt closure device issue. USAF BG Harry E. Goldsworthy, the Director of Production from Office of the Deputy Chief of Staff – Systems and Logistics, indicates that neither the Springfield or Colt bolt closure device designs are acceptable. USMC Chief of Staff LTG Wallace M. Greene, Jr. states that the Springfield bolt closure device is unacceptable. Moreover, the device is considered to be non-essential.

Colt counsel H.H. Owen states that the Colt-Fairchild agreement does not allow Colt to negotiate TDP rights. The Government would need acquire TDP rights directly from Fairchild. In negotiations, J.C. Linnberg indicates that a price of $112 per rifle would be acceptable to the government. Linnberg further advises that Colt offer an incentive type contact as an alternative.

J.C. Linnberg writes memo titled “AR-15 Procurement.” Linnberg indicates that Yount had been consulted as to the attitude of higher authority regarding rifle delivery of 5,000 versus 10,000 per month. Yount indicated that he was instructed to pursue 10,000 rifles per month for mobilization capability. Yount was then asked to substantiate the need of the higher rate as it would result in increased costs. Yount declined to do so as it would involve classified documents.

Colt ultimately rejects the Army’s RFQ on the issues of providing the TDP and manufacturing rights. Colt President David Scott states that they will only consider providing the TDP and manufacturing rights if the government orders more than 500,000 rifles.

The CDC publishes “Troop Tests of Special Purpose Individual Weapon (SPIW).”

Colt threatens to dismantle the AR-15 production line due to the lack of an official contract for further orders.

A meeting is held in the office of the ASA(I&L) Ignatius regarding Colt’s refusal to negotiate manufacturing rights for production of the AR-15. Also in attendance are DASA(I&L) Tyler Port, MG James A. Richardson III – OASA(I&L), MG Elmer J. Gibson – AMC Director of Procurement and Production, COL Williams – OASA(I&L), COL Walter J. Woolwine – Executive Officer OASA(I&L), LTC Frank A. Hinrichs – OASA(I&L), LTC Arthur G. Moors – Project Manager Staff Officer – AR-15 Rifle, and AMC General Counsel Kendall Barnes. After consulting with DASD James N. Davis by phone, ASA Ignatius advises deleting the RFQ‘s requirement for the TDP and manufacturing rights for FY 1964 procurement. However, these should still remain an issue for follow-on procurements. LTG Besson is informed of the change, and he concurs with the decision. MG Lynde and LTC Yount are advised to proceed as advised.

Secretary Vance sends McNamara a memo titled “AR-15 Rifle.” Vance indicates continuing disagreement between the services over the bolt closure device. However, Colt is said to have a promising design. Also discussed is the slam-fire issue. Vance notes that Colt is offering a new firing pin design with a spring. Vance recommends delaying the AR-15 contract award by two months to allow for additional tests be made on each of Colt’s designs.

McNamara replies to Secretary Vance in another memo titled “AR-15 Rifle.” Given imminent closure of Colt’s production line, procurement must go forward. The USAF can get the AR-15 without the bolt closure device, and the Army can have their own version. However, if testing indicates that the bolt closure device is not necessary, the Army can switch to the USAF version.

MG Lynde is briefed regarding the on-going price negotiations with Colt. MG Lynde approves the current prices and directs the preparation of an award approval for submission to his superiors.

MG Lynde then appoints his deputy BG Anderson as the contracting officer on an one-time basis for the upcoming award to Colt. MG Lynde explains that he will be absent at the contract award.

WECOM sends the memo “Submission for Approval of Award of Contract for Rifles, 5.56mm, M16” to Secretary Vance.

The USAIB publishes the report “Product Improvement Test of ArmaLite AR-15 Rifle (Test of Bolt Assist Device).”

The USAF orders 19 million rounds of MLU-26/P from Remington. Soon afterwards, Remington asks for permission to substitute WC846 for IMR 4475.

MUCOM suspends procurement of 5.56mm ammunition over continuing issues of primer sensitivity.

The BRL publishes “An Effectiveness Evaluation of the AR-15 Rifle with a Muzzle Attachment and Comparison with Other Rifle Concepts.”

The USAF and Aberdeen each order a pair of Stoner 63 for testing.

Springfield’s contractor for the multi-shot SPIW grenade launcher completes fabrication and test firing of its first prototype. The tests reveal magazine and extractor problems. In addition, the sighting and triggering methods require correction for satisfactory use at any angle of elevation. Moreover, the weight of the prototype is well above the estimate, and the potential for weight reduction appears limited without the use of lighter materials. The contractor is requested to investigate the use of magnesium and plastic. The dates of launcher delivery is rescheduled to fit in with the rescheduled SPIW rifle delivery dates.

The US Army awards Colt with a $13,296,923.41 contract for 104,000 rifles. DA-11-199-AMC-508 includes 19,000 M16 for the USAF and 85,000 XM16E1 for the Army and Marines. (Ironically, this “one-time” buy will be amended multiple times over the next two years from 104,000 to a grand total of 201,045 rifles.) Rifle deliveries are to begin in March 1964 and end in April 1965. Eleven modifications are made to the rifle design prior to the start of production.

Aberdeen’s D&PS publishes the report “Product Improvement Test of Bolt Assist Devices for Rifle, Caliber .223, AR-15.” Three models of charging handle bolt assist devices for the AR-15 rifle were evaluated for effectiveness in manual extraction and bolt closure operations. A plunger-type bolt closure device was also evaluated. The devices were tested for operation under various adverse conditions, and other special tests were also conducted. Only the plunger-type bolt closing device provided an effective means for closing the bolt under adverse conditions. The modified charging handle did not provide adequate means for extraction operations under adverse conditions. It is recommended that the charging handle bolt assist device tested not be adopted.

Frankford Arsenal finalizes specifications for the XM197 High Pressure Test cartridge. These are loaded with a heavy charge of Hercules Unique. Also drawn up are the specifications for the XM199 Dummy cartridge.

WECOM decides to negotiate a contract with GE for Miniguns chambered in 5.56mm and the XM144 SPIW cartridge.

LTC Yount grants permission for the USAF to accept lots of MLU-26/P loaded with WC846.

The USAIB publishes the report “Product Improvement Test of XM16 Rifles.”

Results of field testing of Colt’s bolt closure device are presented to the TCC. The Army Staff’s representative recommends going forward with procurement of rifles with the device. The final price is negotiated with Colt for inclusion of the bolt closure device.

In a memo titled “Bolt Closure Device,” LTC Yount writes DCSLOG LTG Colglazier informing him of the negotiated price for the bolt closure device, and indicates that the final decision on the bolt closure device must be forwarded to Colt by December 15 in order to be incorporated in scheduled production.

WECOM issues a Quality Assurance Letter of Instruction (QALI) to the Boston Army Procurement District regarding quality verification of Colt’s military rifle production. The letter does not specify a specific requirement for product inspection.

AGILE discontinues the refurbishment of their original AR-15 test weapons and the collection of related data. The AR-15 were undergoing refurbishment at the ARVN 80th Ordnance Rebuild Depot. AGILE had hoped that repair-parts usage data obtained from the refurbishment program would be of considerable value in determining the appropriate number of repair parts to procure for the recently adopted M16 and XM16E1. In addition, other data was being compiled under field conditions on wound effects, malfunctions, and parts failures, together with the causes for the latter, and suggested modifications for correction.

Frankford Arsenal publishes “Eighth Memo Report on AR-15 Rifle-Ammunition System.” Frankford notes excessive fouling from two commercial lots of ammunition loaded with IMR 4475. The ammunition was not produced under the Army’s TDP requirements. Primer composition is noted as a possible cause. The ingredients in question are antimony sulfide and calcium silicide.

The USAF Marksmanship School publishes “Evaluation of M16 Modification – Firing Fin Retaining Devices.”

After a comparison of all tests done by the Army, USAF, and Colt is made, the TCC agrees to adopt a modified lighter firing pin.

CDC sends to ACSFOR LTG Harrell a letter titled “Machine Gun for Rifle Platoons.”

Engineering tests of the Stoner 63 begin at Aberdeen.

AAI delivers three Model #4 fixtures to Springfield.

(Next: 5.56mm 1964)

by Daniel E. Watters, Small Arms Historian
Post questions or comments at The 5.56mm Timeline’s Facebook page.

Document History
Publication: 12/10/1998
Last Revised: 05/17/2009


Author’s Note
This article was originally published at The Gun Zone — The Gunperson’s Authoritative Internet Information Resource. My friend and mentor Dean Speir has graciously hosted my articles at TGZ for nearly 16 years. These articles would likely have never appeared online without his constant encouragement and assistance. 

With TGZ’s closure in early 2017, Dean encouraged me to find a new home for my scholarship so it wouldn’t be lost in the dustbin of the Internet. Loose Rounds has welcomed me with open arms. In the future, I intend to expand my legacy TGZ articles and add new contributions here at Loose Rounds.


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