When the Army Resisted the M16A2, Part 2 of 3

by Hognose

The M16A2 was adopted by the Marines in 1983, and then by the Army in 1986. Shortly before its adoption, an Army contract analyzed the M16A2 — and found it all wrong for  the Army. The report is here: http://www.dtic.mil/dtic/tr/fulltext/u2/a168577.pdf

This is the second of a three part series. In the first part, yesterday on WeaponsMan.com, the Army contractors noted the specific solutions implemented on the A2 and the problems the Marines solved thereby, but complained that the problems and solutions were too USMC-specific. In this part, we’ll discuss just what they thought was wrong about the Marines’ product. In the third part, which we’ll post tomorrow, we’ll list the modifications that they suggested in lieu of or in addition to the A2 mods.

As we recounted in yesterday’s post, the Army let a contract to analyze the Marines’ product-improved M16A1, originally called the M16 PIP (Product Improvement Program but in November 1983, type-classified as the M16A2. Did the A2 meet the Army’s needs for an improved rifle? The contractors recounted 17 improvements in the A2 versus the A1, and traced those improvements back to four or five fundamental goals of the Marine program: more range, accuracy and penetration at that range, more durability, and a burst-fire capability in place of the full-auto setting.

The Army contractors recognized what the USMC had done — and damned it with faint praise.

The M16A2 rifle was developed and tested by the U.S. Marine Corps. The purpose of this present analysis was to evaluate M16A2 rifle features as they relate to U.S. Army training and combat requirements. It was found that the M16A2 did not correct major shortcomings in the MI6Al and that many M16A2 features would be very problematic for the Army. Accordingly, this report provides several suggested rifle modifications which would improve training and combat performance.

The A1 shortcomings that the paper’s authors thought went unameliorated, or were worsened, by the A2 included:

1. 25 Meter Setting: The M16A2 does not have a sight setting for firing at 25 meters, where zeroing and most practice firing occurs.
2. Battlesight Zero: The M16A2 does not have a setting for battlesight zero, i.e., 250 meters.
3. Aperture Size: The M16A2 probably does not have an aperture suitable for the battlesight, e.g., the single aperture used for most marksmanship training, the record fire course, the primary aperture for combat, etc. The 5mm aperture used for 0-200 meters is probably too large and the 1-3/4mm aperture used for 300-800 meters is probably too small.
4. Sighting System: The M16A2 sighting system is too complex, i.e., elevation is changed three different ways, leaving too much room for soldier error.
5. Sight Movement: Sight movements on the M16A2 result in changing bullet strike by different amounts; .5, 1, 1.4, and 3 minutes of angle (MOA)*. The sights intended for zeroing, .5 and 1.4 MOA, are not compatible with old Army zero targets or the new targets being fielded.
6. Zero Recording: The M16A2 does not have a sighting system which allows for easy recording of rifle zero. Also, the zero cannot be confirmed by visual inspection.
7. Returning to Zero: The M16A2 does not have a reliable procedure for setting an individual’s zero after changing sights for any reason, e.g., using MILES or .22 rimfire adaptors.
8. Night Sight: The M16A2 does not have a low light level or night sight.
9. Protective Mask Firing: The M16A2 has not been designed to aid firing while wearing a protective mask.
10. Range Estimation: The M16A2 sight has not been designed to aid in the estimation of range

Let’s consider those, briefly. Note that every single one of those objections relates to the sights. There are no complaints about the other Marine improvements (not even the hated burst switch). Most of the sight squawks were because the sight was different from the sights of the A1, which were pretty much as Stoner, Sullivan et. al. designed them circa 1959 (the earlier AR-10 sights are different, but the later AR-15 prototypes and their descendants all used something extremely close to the M16 and M16A1 sights. (The USAF/USN M16 and the Army/Marine M16A1 differed only in the absence and presence respectively of a forward assist). Even the protective mask issue is basically a sighting problem — with the then current US M17 gas mask, the rifle had to be held canted to use carrying-handle based rear sights.

Complaints 1-5 relate only to the M16A2 sights, but 6-10 are just as applicable to the then-issued Army M16A1.

Even at the time, it was clear that optical sights were better than irons — scopes for distance and red dots for close-in work. Army special operators had already tested — on the flat range, in the tire house, and on the two-way range — such early red-dots and both-eyes-open sights such as the Single Point and the Armson Occluded Eye Gunsight (OEG). In the early 21st Century, universal optics would end the long run of the M16A2, and sweep away all these problems the 1986 Army contractors worried about. But there was no way to predict that in 1986, not with any certainty.

And that’s Part 2 of our story. Tomorrow, we’ll cover the modifications to the M16 that the authors recommended in place of the A2.

The paper is available on DTIC: http://www.dtic.mil/dtic/tr/fulltext/u2/a168577.pdf.