A Dozen Bright Ideas to Improve the M16 – from 1968

M16A1-5

The caption says M16A3, but the illustration looks like an A1.

In the course of our research into primary documents about the M16 program, we have found some interesting things. In March, 1968, the Army and Colt agreed to look into a dozen possible improvements to the M16A1 rifle. Some of these improvements would come to pass right away. Some would come to pass in due course. And some would never happen. The contect of the agreement was the troubles that the M16 series rifle had experienced since introduction, which ranged from changed ammunition that inadvertently sabotaged the gun, to reliability problems that occasioned testy Congressional hearings, to normal teething difficulties. In addition, everyone from end-user riflemen to shop-floor workers had made suggestions for improving the gun. Here are the ideas which, as of March 1968 had been agreed on by the manufacturer and US Army Weapons Command, but had not had a formal RTA.

  1. Buttstock. Change the filler material and provide space for storage of the four-piece cleaning rod and other cleaning equipment.
  2. Magazine. Change the configuration to provide for a thirty-round capacity.
  3. Magazine. Develop new plastic materials and a new follower assembly to permit issue of disposable, pre-loaded magazines.
  4. Magazine Spring. Make the spring of stainless steel to prevent rust and corrosion, thereby increasing magazine life and reliability.
  5. Upper and Lower Receiver. Shot peen the surfaces to provide a more durable finish and to aid in the prevention of exfoliation and inter-granular corrosion.
  6. Handguard Slip Ring and Spring. Redesign the slip ring to allow easier removal of the handguard and cadmium coat the spring.
  7. Ejection Port Cover and Pin. Use stainless steel for these parts to prevent rusting.
  8. Barrel. Chrome plate the barrel to improve resistance to corrosion and metal fouling deposits.
  9. Extractor Spring. Utilize nested springs to provide for longer spring life.
  10. Magazine Cover. Utilize a plastic bag or cap cover to protect magazines from adverse environments. (As of 19 April 1968, two million magazine covers had been delivered from the contractor, 693,089 shipped to Vietnam, and another two million were still on contract.) 1
  11. Rear Sight. Provide for a center index “0”.
  12. Charging Handle Latch. Add Delrin to the charging handle latch material to prevent wear of the upper receiver.
SF M16A1s and ephemera. Click to embiggen (really big file).

SF M16A1s and ephemera. Click to embiggen (really big file).

Numbers 1, 2, 5, the first half of 6, 8, 9, 10 and 11 were done, sooner or later. For an example of sooner, magazine covers were already in use (and soon, the Army issued zip-lock magazine bags). Another “sooner” improvement was the conversion from a chromed chamber only to a fully chromed bore, which helped durability in the face of corrosive conditions (intermittent immersion or soaking) and also in cases of high temperatures. For a “later” example, the handguard slip ring was changed from a cylindrical to a conical section, first for carbines, and later made standard on the M16A2. Likewise, the center windage “0” (implemented as a single long line) became standard with the M16A2 rear sight:

M16A2 sight

Numbers 3, 4, the second half of 6, 7, and 12 were not.

For example, while the 30-round magazine (#2) was developed and fielded (its first significant combat use was the 1970 Son Tay Raid, the magazine-spring redesign (#3) was never done. The current issue spring is chrome-silicon steel, not stainless, although stainless-steel springs are available both as retrofits for GI magazines and in premium aftermarket mags.

The AR platform took many years of modifications & improvements, and incalculable man-years of hard work, by the anonymous toilers of the Weapons Command. The end result is the reliable, versatile and ergonomic weapon we know today, but it took quite a lot of tinkering with the very solid basic design to get us to where we are now.  These 12 proposed mods from 1968 are among the many way stations between design and true success.  (They can be found on pages 11-31 through 11-33 of Appendix 11 to the Report of the M16 Review Panel, 1 May 68. This is the file: ADA953121.pdf).

4 thoughts on “A Dozen Bright Ideas to Improve the M16 – from 1968

  1. Pingback: 1968 improvements on the M16 | The Gun Feed

    1. Hognose Post author

      Thanks, Daniel. Would that be this report here?

      http://www.dtic.mil/dtic/tr/fulltext/u2/835073.pdf

      Title: “FINAL REPORT ON PRODUCT IMPROVEMENT TEST OF SUBMACHINE GUN, 5.56-MM, XM177E2”
      BY GEORGE HENDRICKS ALLAN WILSON
      JUNE 1968

      There’s quite a bit on the 177 on there when I search on Google “XM177 site:dtic.mil” but that looked like the one you described, at a glance.

      ETA: It wasn’t a durability issue but a temperature tolerance issue:

      1.4.2.2 Delrin Charging-Handle Latch. In the -65°F test, one charging handle latch broke during normal use in retracting the bolt. No difference could be detected between the delrin charging-handle latch of the E2 weapons and the metal latch of the E1 weapons with respect to receiver wear.

      Thanks for turning me on to this. There’s some other good stuff there — the test approved the conical slip ring, the cadmium-coated spring, the chrome chamber (already standard in the rifle at this point), and the shot-peened finish and recommended they be introduced in M16 production. [End Edit]

  2. Daniel E. Watters

    As for the extractor springs, the idea of a nested spring design was waived off for the adoption of a rubber insert to support the spring. One clever fellow even proposed eliminating the extractor spring altogether with a giant insert. It looks like someone at IWI reinvented that idea for the Tavor.

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