M4/M16 Problems

One of the things that I did not cover in my discussion of the firefight at Camp Keating was the performance of the weapons there.

Specifically, it appears that the M4s carbines and M249 “Minimi” SAWs started to fail over the course of the fight.

There are a number of links, but this release a draft report from the Combat Studies Institute seems to be the most definitive. (you can see other accounts , here, here, here, and here.

The big issue here is that there are reports of both the M4 and M249 failing as the engagement went forward.

Since both weapons were failing, with one (M4) having a short stroke gas-tube operation, and the other (M249) having a long stroke piston, it’s pretty clear that the method of operation of these weapons are directly responsible for these failures.

Here is what I think is the pertinent quote:

Stafford crawled back up to the protection of the southern post of the OP, where he watched Specialist Bogar put up a heroic defense, nearly single-handedly, with his SAW. Bogar placed it on top of the sandbags, notwithstanding as Stafford noted, “I’m just watching that boulder pop with rounds coming in.” Stafford was badly wounded and drifting in and out of consciousness, but he distinctly remembered, “Bogar had just set his SAW on top of the sandbags and he was just kind of spraying, going through SAW rounds pretty quick. I remember him, loading and spraying, loading and spraying.” At the Crow’s Nest, Specialist Ayers was also going cyclic with the M-240. Stafford also remembered being impressed at the volume of fire that Ayers was pouring out, “I could also hear the 240 going off above me in the Crow’s Nest, because Ayers was just ripping them apart. I could hear Rainey screaming at Ayers not to melt the barrel on the 240 and to control his fires.”

Specialist Bogar fired approximately six hundred rounds at a cyclic rate of fire from his SAW when that weapon became overheated, and eventually jammed the bolt forward. Specialist Stafford noted, “Bogar was still in our hole firing quite a bit. Then Bogar’s SAW jammed. Basically it just got way overheated, because he opened the feed tray cover and I remember him trying to get it open and it just looked like the bolt had welded itself inside the chamber. His barrel was just white hot.”

(emphasis mine)

While I think that “White Hot” is probably an exaggeration, I would think that weapons would fail with the barrel still “cherry” hot, but it appears that there was a lot of shooting going on and the weapons were getting very hot as a result, at which point things like cook-off of rounds, expansion of parts, etc. begin to be a factor.

I will note that the M249 is a weapon that fires from an open bolt, which means that you have to be pumping a lot of rounds down range to get it that hot, so fire discipline, as alluded to in exchange above regarding the M240, a 7.62mm belt machine gun that is essentially the M249’s big brother.

This may have been a situation where the weapons were simply fired beyond their design capabilities.

Part of the reason for this is that the weapons used by both had similar effective ranges.

The AK-47, because of its relative lack of accuracy, is really not effective beyond 200m, particularly in the hands of a typical insurgent, and the M4, with its short (14½”) barrel and relatively light round, lacks lethality beyond that range.

The M16, by contrast, with its longer barrel, would be able to place effective fire on the enemy at more than 300m.

Had the soldiers been using the M16, they would have been able to engage the enemy before the enemy could engage them, and it is not entirely clear to me (please, someone educate me) why the troops were issued a carbine in a non-urban area where engagement distances would likely be longer.

Additionally, it appears that the position was located primarily due to non-combat considerations, which made it less defensible than it should have been.

All of these contributed to a very intense firefight, and it appears that the intensity of the combat was a significant cause as to the failures of these weapons.

Simply put, a personal weapon, or a squad automatic weapon, are not designed to throw that many rounds down range in that short a time.

One question that is not addressed in this report, at least not in this early draft of the report, is whether fire discipline was maintained, or if the troops were reverting to “spray and pray”.

My guess is that fire discipline was maintained, at least to the degree that discipline is possible when you are being attacked by a heavily armed force that outnumbers you, but I have no direct military or combat experience to evaluate this.

That being said, I think that the M4 should be replaced. Most of the other modern western armies, the Germans excepted, have switched to a Bullpup design, and as such, they have longer barrels, and shorter overall lengths than the M4.

See the table below for a comparison:

Weapon Barrel Length Overall Length
M4 14.5 in 29.8 in (stock retracted)
Tavor T.A.R-21 18.1 in 28.5 in

Additionally, while there are advantages to gas tube operation, generally lighter weight and better accuracy because there are fewer moving parts, one consistent complaint about the AR-15 and its children is that the weapons require meticulous, almost obsessive cleaning.

I admire the breakthroughs that Eugene Stoner made when he created the weapon, and many of those innovations, the use of plastics and high-strength lightweight alloys, continue today, but I think that the use of the gas tube has been shown to be problematic.

That being said, I would favor moving to a new weapon, as opposed to something like the gas piston retrofit, as the existing weapon has problems that are inherent in the design (i.e. barrel length and overall length).

In my perfect world, the Army and Marines would purchase one of the Bullpups already in service, as opposed to developing a new weapon itself, but given the nature of defense procurement in the US, particularly the Army Ordinance’s rather parochial view towards foreign weapons, I think that this unlikely.

Note: I have never served, and I’ve never shot anything more substantial than a .22 short rifle for in a riflery class in summer camp, so if I am wrong, please tell me in the comments.

All I ask is some detail. Don’t tell me I’m an idiot, show me that I’m an idiot.

2 comments

  1. Dave says:

    <p><span><span>If all weapons used the same 5.56×45mm ammo then all used the same primer and powder.<span>  T</span>he main problem is incomplete combustion of the powder, carbon buildup plus oil plus dust.<span>  </span>This is the same problem that the cartridge in the M16/M4 has had since the 1960's.<span>  </span>The M16 was designed with rod powder and the inventor specifically said do not use ball powder, use rod powder.<span>  </span>Has anything been done to speed up the combustion by changing either with a primer powder or both?.</span></span></p>

  2. Matthew G. Saroff says:

    Well, the SS109 replaced the 1960s vintage round, with a higher sectional density (it's longer), and along with tweaks to the propellant, it should have fewer unburnt residues.

    I still say, go with a piston and a bullpup.

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