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The M14, Not Much For Fighting ( A Case Against The M14 Legend )

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Photo above is the M14 with its Technical Data Package. Shared from Daniel Watters.

Go on to any gun forum, and it won’t take you long to find people willing to tell you how great the M14 is. How accurate, like a laser, tough as tool steel with no need to baby it or clean it. Powerful as a bolt of lightning, and how well loved it was by those early users who refused the M16 because they wanted a “real” weapon made of wood and steel… But, is all that really true? Maybe it is a triumph of nostalgia over common sense and reality. One truth is, it was never really liked as much as people think they remember.

The M14 was having major problems even before ARPA’s Project AGILE and a Defense comptroller reported the AR15 superior to the M14. The famous Hitch Report stating the AR15, the M1, and the AK47 superior.

The study indicates that the AR15 is decidedly superior in many of the factors considered. In none of them is the M14 superior. The report, therefore, concludes that in combat the AR15 is the superior weapon. Furthermore, the available cost data indicate that is also a cheaper weapon. – ARPA

Although analyzed less thoroughly, the M14 also appears somewhat inferior to the M1 rifle of WW2 and decidedly inferior to the Soviet combat rifle. the AK47. – Hitch Report

“Report on Tests for Ad Hoc Committee on Accuracy and Testing of 7.62mm Ammunition and M14 Rifles.” Seven rifles each from batches accepted from H&R, Winchester, and Springfield Armory had been shipped to Aberdeen for testing to find and cure the causes of the M14’s inability to meet its accuracy requirements. Examination and testing of the 21 rifles uncovered the following:

All of the rifles from Winchester and H&R exhibited excessive headspace.

All of the rifles had loose handguards.

95% of the rifles had loose stock bands.

90% of the rifles had loose gas cylinders.

75% of the rifles had misaligned op rods and gas pistons.

50% of the rifles had loose op rod guides.

50% of the rifles had op rods that rubbed the stock.

Three rifles had barrels that exceed the maximum bore dimensions.

Only three rifles had an average bore diameter that fell below the accepted mean diameter.

One rifle was found to have a broken safety while another had a misassembled safety spring.

One rifle had a misassembled flash suppressor, which was actually contacting bullets during live fire tests.

A barrel from each manufacturer was sectioned for examination of the bore and chrome lining. The chrome lining was out of tolerance (uneven and on average too thin) in all three barrels. The H&R barrel also failed the surface-finish requirements. During accuracy testing, the M14 rifles produced greater group dispersion and variation in the center of impact than the control rifles (two T35 and two AR10). NATO testing was quoted indicating that the Canadian C1 (FN FAL) and German G3 were less sensitive to variations within and among ammo lots. Shutting off the gas port in the M14 rifles resulted in an average 20% reduction in extreme spread compared to those groups fired with the gas port open. This also reduced the variation in the center of impact. The design of the flash suppressor was singled out as a cause of inaccuracy.

An M14 Rifle Cost Analysis report that gave rounds used and overhaul schedules from rounds fired states M14 annual usage is 3,500 rounds to overhaul and 599rds MRTF. Does not sound much like a hard use fighting gun…

Full PDF of the honest technical Report that does not paint the M14 in a rose colored light, can be found here. http://www.dtic.mil/dtic/tr/fulltext/u2/677383.pdf Take note of Page 32.

Production of the M14 was long and troubled. The cost of the weapon rose beyond claims of being able to produce it cheaper and with the same machinery used to make the M1. The story of the long tax money gobbling nightmare of the M14 is known to those who study the deep history of military weapons, and I encourage anyone interested to look into themselves but I am not going to go into that this time. For this post, I will be talking about the current niche the M14 is still hanging on to.

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After the M14’s near-complete death of cutting-edge combat use, the Army still wanted it as their sniper rifle. Of course, many systems were tested by the Army during the Vietnam war, including the USMC M40 sniper weapon, For debatable reasons, the Army decided the M14 was the way for them. This is where the rifle begins to show.

The USAMTU had been working with the M14 for years for use in competition and sniping. Indeed the AMU knew that the Army would need a sniping weapon even before the officers in charge did. So they had been working on the National Match M14 for a while.

The procedure to turn an M14 rifle into the M21 or the National Match service rifle is so long and complicated I have little desire to try to repeat it here. See “The Complete Book of US Sniping” by Peter Senich if you want all the details. I will say the process was time-consuming and expensive, and that is not even starting to discuss the search for an optic system to go on the XM21. It produced a rifle capable of 800-yard kills and usable accuracy. For a while at least.

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Over the next several years, the Army spent millions trying to perfect the system while it was used as the service rifle in high power. Between those two pursuits, some interesting things were learned about the accurized M14. It turned out it was not as rough and tough as some think. To keep an M14 made to NM-spec accurate, it requires careful tuning and extensive PM. If you doubt this, go to your local range and find a high power shooter who still uses one. Ask them if you may look at the rifle and grab it by the top handguard and watch the fellow go from deathly white to red with rage and horror of what you just did. It needs to be carefully babied. And the Army spent millions and years relearning that lesson over and over with the M21 until finally dumping it for the M24 in the later 80s.

Though people who have many believed the Military and the end users long for the return of this big heavy beast, this is not really all that true. this is best illustrated during the time period in the late 80s to the late 90s of the USMC’s DMR program when so many tried to bring it back as the DM rifle or the Sniper teams spotters weapon.

Around, during or a little before this time, the Army Rifle team commander decided since the Army’s standard issue service rifle was the M16, then that is what the Army service rifle team needed to be, and should be using. The AMTU armorers put their heads together, took some tips from civilian high power shooters who had already woken up and got by the absurd notion that service rifle meant “wood and steel,” and soon after the Army was beating the USMC rifle teams at Camp Perry by a long shot. Not long after, the Marines found themselves going to the M16 for service rifle to keep up. Few people, who want to stay competitive have looked back. Especially after the development of the 77 and 80-grain HPBT match bullets.

But, the DMR program is where the trouble of the M14 as a precision combat rifle really became clear.

To quote Lt. Colonel Chandler owner of Iron Brigade Armory and former Officer in Charge of many USMC marksmanship and sniping programs:

“Remember that the US Army struggled for more than twenty years to transform the M14 into a sniper type weapon. The Army finally abandoned all attempts to salvage the M14 rifle. Continued use of the M14 as anything other than a drill rifle is better described as DISASTER. ( emphasis Chandler’s) The M14 is old and has never been more than a modified M1 Garand. “

“Unfortunately the M14 rifle is costly to modify and modification requires many man-hours of skilled labor. In the field, the M14 cannot maintain accuracy. The Army refused to admit that they could not solve the M14’s accuracy problems and wasted two decades attempting to make a silk purse from an old infantry rifle. Milspec spare parts are no longer made and those that can be found are often inferior, and ill-fitting. “

“The M14 requires constant ( continual ) maintenance. Maintenance on an M14 progress geometrically. That means if you double an M14 rifle’s use, you quadruple its maintenance. “

“The world has moved beyond the M14. The weapon remains a standard piece only because it is used ( though less and less) in service rifle competition marksmanship, which is very different from field use. If anyone recommends it, run them through.”

“It is ironic that some of the USMC rifle competitors whose accurized M14s have been consistently waxed by the Army’s M16s are supporting the use of the M14 as accurate rifles.”

“As we discuss the costs of bringing scoped M14s onto the line in large quantities, allow me another digression. The M14 is a bitch to keep in tune, and an untuned M14, no matter who did the accurizing is about as accurate as a thrown rock. Unless the M14 is continually babied it will not retain accuracy. ( this is an important note from LT Col Chandler for those who fire 100 rounds a year and tell you the M14/M1A is wonderful). Imagine the hardships and brutalities a scoped M14 will experience as a DM weapon in combat. (One recalls the story of Carlos Hathcock walking back to the shoot house and starting to pass out, another Marine grabbed the accurized M14 and let The Ultimate Sniper fall face first into the asphalt. Letting a weakened man fall to keep the pathetic NM M14 accurate). No M14 ever built will stay accurately zeroed and tight group shooting, (meaning close to MOA) under field conditions. ”

Chandler goes on to point out the requirements in specially qualified armorers who know how and can keep an M14 accurate and how even in the early 2000s those men are almost extinct in the USMC accuracy and Sniping world.

“To create accurized M14s with their special mounts and scopes and stocks, chassis etc. will cost more than twice as much as modifying M16s. Worse, while maintenance on M16s/AR15s remains routine, the M14s require more than six times the labor and dozens of times more replacement parts to maintain. Anyone who claims that going to the M14s is economically comparable to adopting the M16s is utterly ill-informed or is simply parroting the party line.”

“Allow us to remind again that the US Army, which has far more research, repair, and maintenance capability than the Corps, tried for twenty-two years to make the M14 into an accurate rifle. “

Compelling stuff from a man who spent most of his career working around the best weapons and men in the world when it comes to accuracy, sniping, and the marksmanship community. But he goes on:

“So how on earth does this bizarre situation develop?” ( the idea the M14 is still some wonder rifle fit for serious use for anything beyond the parade ground of the nostalgia of the thing)

“How an idea germinates is difficult to determine. Perhaps a shooter who liked the M14 dreamed it all up. You know-==” A great old piece. let’s put it back to work!” The M14 concept has been allowed to develop into a full-blown program because individuals involved were sometimes not weapons experts, possibly not infantry experienced at all and almost never sniper trained. The fact is line NCOs are not marksmanship literate. The M14 DM program is driven by those type of NCOs. NOT SNIPERS. “

“The M14 in all its forms has been a pain in the ass to its users, and when Marines speak candidly they do not proclaim their M14s to be ” the finest DM rifle in the world “. They refer instead to inability to stay zeroed and almost as often, to frustration in keeping their weapons in service due to the unending, never easing, repair requirements.”

Chandler went on to talk about how, after retiring from the USMC and starting Iron Brigade Armory, one the best makers of combat-hardened, nearly bombproof sniper rifles in the world and the makers of the legendary DARPA XM-3 sniper rifle system. He gathered and employed the worlds best retired USMC 2112s that he could find and attempted to make a tough super accurate M14s. Making money no object in the pursuit in an attempt to see if it could be done.

” We, who have no bottom line, to worry about who can and do use the ultimate materials and the finest skills known cannot expect our M14s to maintain accuracy under combat conditions. We do not believe the M14 design allows accurizing that is combat condition durable. ”

Chandler’s quotes and feelings on the M14 as well as his belief the M16 with an optic is the ideal Sniper’s Spotters weapon, as well as DMR, can be found in “Death From Afar Vol. I-IV” as well as “The One Shot Brotherhood” and various other technical publications such as Precision Shooting magazine as well as technical papers spread internally in the USMC.

The M14 remains popular in the civilian world and not just from service rifle shooters. It still has a life among collectors, plinkers, and even serious shooters. The new variants trying to breathe life into it as well as pictures on the news of M14s forced into use in the first half of the GWOT. Some still get caught up in its legend and its lore. The romance of the piece has lulled many away from the fact it is not a fully capable modern fighting tool. Many of its fans overlook its many drawbacks. The safety needing a finger inside the trigger guard and to push forward to deactivate. The limited capacity and reload time that is slow (which when compared to a practiced user of an M1 Garand is actually slower to reload than an M1).

The maintenance, as Chandler said above is a nightmare if the gun is used often. Every time it comes apart, the bedding gets worse and worse. It may seem like no big deal for a combat weapon, but it is. The gun is heavy in all its forms and is as slow as a monkey doing Chinese algebra compared to the faster more natural manipulations and ergonomics of better designs. The oft-used excuse of “I will pick them off at 500 yards before they get close enough to worry about” is absurd. The last 15 years have shown very few cases of infantrymen laying prone and picking off enemy soldiers at 500yds. It is laughable to consider using the M14/M1A on your lonesome in an urban or CQB role. Sure, some SOF have done it, but they have someone covering them.

While the ergonomics of the M14 are already not wonderful for modern TTPs, the use of some of the newer stocks, like the Sage exaggerates the difficulty for anyone other than a giant who drags his knuckles when walking Never mind the astounding increase in weight, let alone the cost of such an “upgrade”.

Howard, fellow LooseRounds writer, co-owner with me of this website, friend, and USMC rifleman, and Iraq war vet gives his opinion and experience with the rifle as well as what he observed of it in Iraq.

“My experiences with the M14 type rifle lead me to have little interest in it. I owned a Springfield Armory Bush rifle that had various issues. I sold it to a guy who liked M14s. Later I received a SOCOM II in trade and found it overly heavy and was not a gun I would want for long distance shooting or for close quarters.

While I was in the military, I did see a couple of M14s in or near Abu Ghraib prison. Guys liked the idea of the rifle but didn’t want to carry them. They were often left in vehicles or in guard towers. Issues included lack of support gear(mags, mag pouches, etc), and that the majority of the soldiers and Marines didn’t know how to use or maintain the M14 rifles.”

Lt. Col. Chandler would feel a sense of deja vu I have no doubt. Maybe even frustration that so many refuse to see the evidence from many decades.

Other opinions, from a man who was more or less my mentor in the olden days. An SF vet from Vietnam who used the M14 in training and in his early days of combat. He went on to be a ballistic reconstruction expert. Tested Federal 22 Long Rifle match ammo to be used in that years Olympics and T&Ed guns for Ruger and High Standard. In addition, he is an accomplished BR and service rifle shooter as well as bullseye small bore and pistol.

When I first got to Vietnam, I was scared to death of the M16. I feared a jamming M16 would get me killed. Poison snakes, spiders, and a jammed M16 was such a worry to me I opted to carry an M60 on my first LRRP patrol. Later I learned to love it. I hated the M14, it proved not as reliable and was heavier and I could not carry near enough of its ammo. When it comes to combat I would walk over 100 of the best M14s ever made for one good M16.”

My own Father had this to say. Dad was in Vietnam from 1967-’68 in the 4th Infantry Division.

“I liked the M14 in basic. It was the first semi-auto I had ever fired. It got old carrying all that weight fast running everywhere all day and night. I qualified expert with it. Once I was issued an M16 right before we overseas, I never looked back.”

For every person who has told me how great the thing is, I have found two who had nothing but misery and bad experiences from it. I myself among them.

Among the other myriad issues of using the M14 as a match rifle and DMR as well as anything else required by it in combat, more recent problems popped up. Since most users trumpet the excellent accuracy of the M14 and its use in combat as a hard-hitting accurate battle rifle, this means military grade match ammo to take advantage of its legendary long-range man-killing accuracy.

Quotes below from.

7.62 NATO Long Range Match Cartridges
By Name Removed at request of author.

“With the start of the Gulf War II in 2003, the high temperatures encountered in Iraq (in excess of 115 degrees F) began to produce some M14 op-rod failures due to excessive pressure at the gas port. Both the Army and Marines found the range marking on their scopes to be off of calibration with the higher velocity M118LR loads in such desert conditions. The result was a decision to reduce the load to a more moderate level.”
“Although this cartridge remains the current M118LR standard, it apparently still suffers from excessive velocity variation as the temperature changes and less accuracy than might be desired for truly precise shots at mid-range to long-range distances. The specification for M118LR requires 14 shots in less than 8 inches at 600 yards.”

The military did get the bugs worked out on the ammo eventually so that is one less thing to worry about if you are in a fight and can get your hands on the good stuff.

“The MK316 ammunition is essentially the finest possible mass-produced match ammunition, comparable to the hand loads utilized by the various service MTUs. The cost is higher than M118LR, with a government cost of 78 cents per round for the MK 316 Mod 0 rather than 55 cents for the M118LR (2009 prices).”

The question is, why waste such ammunition in an M14 when 7.62mm pattern AR type rifles are now easy to get, more accurate, more familiar vastly cheaper and much easier to work on. Not to mention being familiar with the vast majority of military and civilian users.

The M14/M1A will be around for as long as people will continue to buy them. Certainly, there is nothing wrong with owning them liking them and using them. By no means is it useless or ineffective. But its legendary reputation is something that needs to be taken with a grain of salt and careful study of the system if you intend to have one for a use your like may depend on.

If you are curious, previous posts on shooting rack-grade M14s and custom service rifle M14s with Lilja barrels fired at 1,000 yards can be found here on Looserounds using the search bar. There you can read of the M14/M1A compared against the M1 Garand and M1903.

M14 Service Rifle pic

Thanks to Daniel Watters for additional information, sources and help. You can read Daniel’s excellent indispensable resource “A 5.56×45 Timeline” at the following link if you are a serious student of US weapons development history. http://looserounds.com/556timeline/

A New “Old” Surprise From Colt At SHOT

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Colt has shown a surprise to most this year at SHOT.  Many will recognize the Colt hammerless.  Now self respecting gentleman from early last century would leave the house without this sleek shoot in his suit pocket.

 

Phots courtesy of Dave, good friend to Looserounds who helps us out during SHOT and many other times.

 

 

Price not set. Limited. Some blue some parkerized. Some will be matching numbers to the original guns and come with a letter saying which officers carried them. Super cool.

 

 

 

Colt Brings Back An Old Tradition

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Colt has announced they are bringing back a service they were once very well known for.  Anyone who knows their gun history knows Sam Colt was fond of special addition and presentation models of his revolvers.  The practice certainly still exists and Colt does still make special runs, but usually from a third party like Talo.   Now, you can can order up something special for your group of friends, co workers or sewing circle.    The thing that really stuck out, is now you can have a special M4 ( 6920) made up.

WEST HARTFORD, Conn. (January 12, 2015) – Colt’s Manufacturing Company, one of the world’s leading designers, developers and manufacturers of firearms, is proud to announce the launch of its new Commemorative Program. The Colt Commemorative Program allows civic groups, law enforcement units, military personnel and other government agencies to order heirloom-quality, customized Colt firearms.

“The Colt Commemorative Program is an excellent way for a group of close-knit individuals to honor the special bond they share,” said Joyce Rubino, Vice President of Marketing for Colt’s Manufacturing Company. “This program is a completely new offering to civic groups, and we look forward to sharing in their expressions of pride through a custom Colt firearm.”

Commemorative firearms in this program typically include the Colt 1911 (model O1091) or the LE6920 rifle. However, other models may be available depending on the specific project request. A minimum of 25 firearms is required per Commemorative Program order.

 

To submit a request to Colt’s Commemorative Program, please complete the online contact form on Colt’s website under the Customer Services section.

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I doubt the level of customization seen above is the type most can expect, but  having seen examples of special runs  I have seen in the past 15 years, you could have a fairly large variety of choices.  I have always liked the idea of this kind of thing, and I hope to see it come back.    With a requirement of 25 pieces at a minimum, it would seem few groups other than wasteful government agencies will have benefit of such programs.  Who wouldn’t want to have a special handgun to  remember the time the president’s security detail enjoyed Brazilian prostitutes !

 

 

May your first day in hell last 10,000 years, and let it be the shortest.

I think it is possible that there are people in the world you can hate so much that it is impossible to find a word for the intensity of that hate.  It is like the heat of a million exploding suns.  No stranger to hating people myself, I can not think of anyone I hate more than my ex wife  or osama bin laden ., except for this thing.   Certainly, if you read this website, you are the kind of person already familiar with it.    obama better watch out, he has a strong competitor easing up on his position.

 

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If you have a twitter account, I would suggest twitting your thoughts to this twit.

The Big Lie About Wanat (COP Kahler), Part 2 of 2

Part 2 of the debunking of the absurd myth that the M4 has caused the death of US military people due to failures.  Once again this is the sole work of the writer from www.weaponsman.com,  THE technical website on all things military weapons related, among other topics. We again highly recommend all follow them.  Part 1 is actually below this post due to the way our website is set up.   Both are long posts but very detailed and worth reading if you are a real student of military fighting weapons.

 

In the enormous1 part one of the series, we reacted to a brain-dead article published in The Atlantic by a retired Major General, who has, since his retirement 20+ years ago, been a lobbyist for defense firms and TV talking head. (Before he got his stars he was an artillery officer). We may have more to say about our brain-dead GO in a subsequent post, but we think we raised some good points about his article. We weren’t the only ones. He also ticked off Nathaniel Fitch at The Firearm Blog, and we heard, also the guys at Loose Rounds (you know, the ones that fire M4s at 1000 yards and make the steel ring? Those guys?), and no doubt there are other places in the gunosphere flaying him. The point of today’s increment is not to make the rubble of the General’s small-arms expertise do a dead-cat-under-155-battery-closed-sheaf-fire-for-effect bounce, but to discuss the technical limits of a shoulder weapon in sustained automatic fire.

Because today is a travel day, this article was mostly-dictated for speed. Therefore, we fear we have some typos we haven’t found. Let us know in the comments.

Sustained Auto Fire and Heat

Many of the problems the M16A1 had in Vietnam, and even in adoption and acceptance prior to Vietnam, were caused by the heat of sustained autofire. It was particularly problematical after powder changes made a dramatic impact on the cyclic rate of the rifle. Indeed, Colt got a contract mod allowing weapons that had a much higher sustained rate than originally specified to be accepted.

Thermal waste is a huge problem for gun designers, and it’s been jamming automatic weapons since Maxim’s day. The heat is generated by the combustion of chemical powder in the chamber in barrel, but also by the metal-on-metal contact between bullet and barrel, which swages the impression of the rifling into the bullet and imparts a spin of hundreds-of-thousands of revolutions per minute to the bullet. The friction between bore and bullet is a significant contributor to barrel heating.

If you were in the service, you were made to memorize something about your rifle being a “shoulder-fired, magazine-fed, air-cooled, selective-fire…” weapon. The “air-cooled” seems like a historical artifact now; the last liquid-cooled small arms were the 1917 Browning machine guns, which were last used in World War II. All modern small arms of all nations are air-cooled. That means that the air around the barrel must carry the heat of the barrel away. Meanwhile, for each round, the barrel gets hotter, because firing’s ability to load up the temperature is greater than the cooling system’s ability to remove heat.  (The original M16A1 had a patented passive design for convection-driven airflow, removing the heat from the holes at the top of the handguard and drawing new air in at the bottom. Designs since then have made efforts to maintain that cooling, with little success).

Because this post is long, and involved, we’re going to split it. Ahead, we describe the bad things that happen when barrels get hot; the results of M4 cyclic rate tests (including instrumented and well-documented tests to destruction), and  Click “more” for the next three thousand or so words, a few pictures, and pointers to where you can find some of the math.

Bad Things Happen When Barrels Get Hot

The peak temperature area in the barrel is usually about three to seven inches forward of the chamber, depending on caliber (according to the references, on 5.56 mm rifles, it’s about four inches). This is where the thermal stress is at peak, and it also has to support all the rest of the barrel (and anything that may be attached to it, from a Surefire to an M9 bayonet), so when the gun is going to fail, it’s probably going to fail near here.

As more rounds are fired, more heat builds up, because it is being added at a higher rate than it can be radiated away. As the temperature rises, bad things happen:

  • You have a risk of propellant cook-off. Weapons that fire from closed-bolt are especially prone to cook-off. At a critical temperature, the powder or primer will self-initiate. As the temperature rises, the amount of time a round has to sit in the chamber to heat-soak to the point that it self-initiates declines. At first it takes minutes, then seconds, then rounds can actually cook off before the automatic firing train fires them, and finally, they can cook off out of battery. Usually other damage disables the weapon by this point. This article at DTIC shows some of the tools the .mil has to model heat transfer, and compares predicted cook-off data to observed, unfortunately in a large-caliber small arm (30mm Mk44 vehicular cannon).  They generated this equation (after Visnov) that shows :

Time to cook off (minutes) = 10.129 x 1025 x (cook-off Temp – degrees C) x 10-10.95

The cook-off temp is a constant for a given powder, and can be experimentally determined by heating the powder on a steel plate.

In the test, they did not maintain continuous fire but bursts of fire according to a firing table, then followed by letting a round sit in the chamber. Their cook-off times in live testing ranged from about 10 to about 30 minutes testing. Note that brass provides better protection from cook-off than aluminum cases, which in turn provide better protection than steel.

In another experiment, Hameed et. al. built a “Chamber simulator” and developed working chamber temperature-time curves for producing cook-offs in a 7.62mm brass case with Bullseye powder. They found that below 170ºC chamber temperature, cook-offs were unlikely, and that by about 240º, the cook-off time was down to seconds.

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[A]n improvement to temperature sensitivity came along in 2005. [Black Hills President Jeff] Hoffman said the last change came after Black Hills technicians noticed some failures to extract (FTX) in their test M4 and short-barreled rifles, and that it was the most difficult problem to solve.

“We initially thought the FTXs were possibly related to higher port pressures,” Hoffman said. “The M4’s port pressure is around 25,000 psi, much higher than the SPR due to the location of the gas port on the respective guns. We looked at brass, powder, everything.”

It finally came down to chamber temperature. The test specification called for the ammo to be baked at 125 degrees for two hours and not exceed pressure limits when then chambered and fired. When Black Hills engineers started firing test guns far beyond the specified rate of fire, the chamber temperatures got much hotter than 125 degrees. In an extended firefight, soldiers could heat up their rifles with a few mags, and then during a lull in fighting, a chambered round would sit in a 200- or even 300-degree environment. That significantly increased chamber pressures and induced failures to extract.

“After we figured it out, I was surprised that it hadn’t come up before,” Hoffman said. “We’ve gone from bolt rifles to eight-round Garand clips to closed-bolt, select-fire rifles. SF guys never had an issue because they are trained to fire two or three rounds per target and very rarely go full auto.”

It only took Black Hills 75,000 rounds to sort out the problem—a chunk of the 250,000 rounds Hoffman figures the company fired developing and lot-testing the load. Finally, the round was issued. Interestingly, the ammo always did meet specs, even the ammo that Black Hills engineers felt needed improvement—they just found a way to make it better. The Navy began changing test specifications based on what Black Hills learned—and shared—during development and testing. The improved round was a hit, no pun intended, with operators in-theatre, and usage went through the roof. Not only did the ammo perform well for its intended purpose—long-range shooting—but did equally well in short-barreled rifles like the M4 (14.5-inch barrel) and MK 18 (10.3-inch barrel), which leads to a discussion of lethality.

  • It can cause the barrel itself to fail next time it is used. At a very high temperature, the barrel is heated until it loses its temper, which can cause an invisible (and undetectable by gaging) failure of accuracy. This was first noted with aerial machine guns in WWII, as we noted here before.
  • If continued, it can cause the barrel to fail catastrophically whilst firing. Stripped of its heat treatment and heated to the metal’s plastic temperature, the barrel droops. At first, rounds extending through it will sort of “hold it up” but soon it will be unable to contain the pressure and will burst.
  • If the barrel doesn’t fail first, heat can cause the gas tube to fail. Weakened by high temps, the tube lets go.

Any gun can cook off. The USN famously cooked off a 5″ on the destroyer USS Turner Joy in 1965 during a Vietnam War shore bombardment, killing three sailors and wounding three more.

Results of M4 Cyclic Rate Tests

Colt has, in fact, tested M4s at cyclic rate to destruction and has made these tests public. C.J. Chivers, a former Marine, has reported on these tests in a long and readable report for, of all things, the New York Times. That report was Part II of a previous report on M4 manufacturing there. We were unable to extract the Colt videos from the Times page, but it’s very much worth reading, anyway.

After the Colt tests, the Center for Naval Analyses did a report. We don’t have the report, but Kirk Ross at the US Naval Institute’s Proceedings Magazine did an excellent and thoroughly-documented synthesis of the then-known information, including the CNA report and the Colt tests, a DOD  survey of weapons users, and SOPMOD program office documents. Ross’s article is an excellent short piece on these issues and we strongly recommend it.

A lot of what we know about the M4 under duress comes from mid-1990s research. In the 1990s, as the then-new M4A1 carbine began reaching special operations units that shot them a lot, they began blowing them up. In June, 1995, 10th SF Group had two cook-offs. In September, the 1st Battalion of the 1st SFG reported multiple problems, including cook-offs. In May, 1996, 7th Group blew one up in its then-home-station of Fort Bragg. In August, 1996, 3rd Group blew one up on an African JCET; one USSF was injured by gun shrapnel. 5th Group and the 1st Ranger Bat also blew up guns around this time, and that began to worry SOF soldiers and leaders — and the armament procurement guys. The Army resolved to test M4s to destruction to determine what was going on. The one thing they knew was that the destroyed guns had been fired a lot, primarily full-auto fire at cyclic rates, often “burning up” excess ammunition at the end of an exercise (wasteful, but the Army makes it very difficult to turn back in unused ammo, and the Air Force is snippy about transporting it).

In 1996, ARDEC’s Jeff Windham conducted tests-to-destruction to determine whether, as then rumored, M4 barrels were more prone to failure than the M16A2 barrel. These were early M4A1s with the M4 profile barrel (like the one we carried in Afghanistan), and the M16A2 controls in the test were modified to fire full-auto by subbing in M16A1 fire control parts. The guns were fixtured and fired full-auto. The intent was to fire one of each fully-instrumented weapon to failure. Initially, an M16A2 was destroyed:

The M16A2 was fired continuously using 30 rounds bursts. Shown in Table I are the rounds to failure, time to failure and maximum barrel temperature of the barrel. Muzzle flash increased and there was a distinct change in the sound of the weapons firing approximately 30 rounds before the barrel ruptured. There was also noticeable drooping (about 1 inch at the muzzle) of the barrel just prior to the barrel rupture. The barrel ruptured at 491 rounds with an approximately ½ inch hole in the top of the barrel about 8 inches in front of the chamber. The barrel was bent approximately 5 degrees and bulged in several locations along its length (see figures 4, 5, and 6). A plot of barrel temperature versus time at each thermocouple location is shown in figure 7.

Given the hypothesis that the M4 would die before the A2, Jeff fixtured the sacrificial M4A1 and set up 18 magazines, containing 540 rounds, and then fired them. But while the barrel was ruined, it didn’t actually burst:

The M4A1 Carbine was fired for 540 rounds. It was thought the M4A1 barrel would rupture well before this point, therefore only 540 rounds were loaded for firing. This weapon’s barrel was noticeably bent and bulged at the end of the test (see figure 8). A plot of barrel temperature versus time at each thermocouple location is shown in figure 9.

m4a1_fired_to_destruction

Oops. Back to the testing bench, with another M4A1 selected as a sacrifice to the gods of knowledge.

A second M4A1 Carbine was fixtured for testing and fired until barrel rupture. Muzzle flash increased and there was a distinct change in the sound of the weapons firing approximately 30 rounds before the barrel ruptured. There was also noticeable drooping (about 3/4 inch at the muzzle) of the barrel just prior to the barrel rupture. The barrel was ruptured at the 12 o’clock position approximately 4 inches in front of the chamber. The rupture was approximately 1V4 inches long and 5/8 inches wide. The barrel around the rupture was bulged out about 30 percent larger than its normal diameter. The barrel was bent at the hole approximately 3 degrees (see figures 10 and 11). A plot of barrel temperature versus time at each thermocouple location is shown in figure 12. There was an approximately 30-second delay in firing of this sequence which can be seen in the temperature plots. This delay allowed additional cooling of the weapon and may have increased the number of rounds to rupture by 30 to 60 rounds.

Here is the Table 1 from the report. The other figures and tables referenced in the quotes are in the report, which is linked in the Sources below, although the photo reproduction is of very low quality.

fire_to_destruction_table_1

SOCOM sent a safety message as far back as 1996, presumably based on Windham’s research (although we didn’t notice if they said that) about cook-offs with sustained fire. It is reproduced in this archived ARFCOM thread. We recall receiving this message with a red-bordered safety cover sheet. The thread poster has good advice. Here are a couple of lines from that message:

Sustained firing of the M16 series rifles or M4 series carbines will rapidly raise the temperature of the barrel to a critical point.

Firing 140 rounds, rapidly and continuously, will raise the temperature of the barrel to the cook-off point. At this temperature, any live round remaining in the chamber for any reason may cook-off (detonate) in as short a period as 10 seconds.

Sustained rate of fire for the M16 series rifles and M4 series carbines is 12-15 rounds per minute. This is the actual rate of fire that a weapon can continue to be fired for an indefinite length of time without serious overheating.

The sustained rate of fire should never be exceeded except under circumstances of extreme urgency. (Note: a hot weapon takes approximately 30 minutes to cool to ambient temperature conditions).

Cook-offs out of battery result from a round which cooks off when the bolt is not locked or a round which cooks off as the user is trying to clear the weapon.

Burst barrels result when the weapons are fired under very extreme firing schedules and the barrel temperature exceeds 1360 degrees Fahrenheit. When the barrel reaches these extreme temperatures, the barrel steel weakens to the point that the high pressure gases burst through the side of the barrel approximately 4 inches in front of the chamber. This condition can result in serious injury.

That is, of course, exactly the failure mode in the first M4 video at Chivers’s report. And this is from a message from 1996, so SOCOM’s weapons experts knew it almost 20 years ago, and more than 10 years before Wanat.

600-700 degrees F is where cook-offs begin, and that’s reached in as few as 140 rounds on rapid semi-auto fire.

Here’s a table with some key temperatures for you:

Temp F Temp C Rounds Comment
230 110 30 semi-auto M855 in M4
278 137 30 full-auto M855 in M4
600 316 140 semi-auto; threshold of cook-off
700 371 ? frequent cookoffs, barrel weakened
1360 737 ~500 semi or full, catastrophic failure
© Weaponsman,com 2015

How to Deal With Heat Limits

The Training Answer: First, every GI should see those Colt test videos and know what his gun can, and can’t, do. While the Black Hills guys were correct in noting that SF/SOF guys usually manually fire single shots or short bursts, even most of them don’t know what happens when a gun goes cyclic for minutes at a time. A good video explaining “why you can’t do that” would be a strong addition to training, not only for combat forces, but for support elements who may find themselves in combat and feel the urge to dump mags at cyclic rate.

The Morale Answer: Every GI should see the same done to AKs as well. There is a myth perpetuated by pig-ignorant people (like General Scales) that the AK series possesses magical properties and that the American weapons are crap. In fact, nobody I know of at the sharp end is at all eager to change, perhaps because the laws of physics and the properties of materials apply just as firmly to a gun originally created by a Communist in Izhevsk as they do to a concept crafted by capitalists in California. If you’ve ever fired an AK to destruction, you know that it grows too hot to hold, then the wooden furniture goes on fire, then, if you persist on firing it full-auto, it also goes kablooey. Not because there’s anything wrong with this rifle, but the laws and equations work the same for engineers worldwide.

The Systems Answer:  As you can see from the Colt videos, if you clicked on over to Chivers’s article, thickening the barrel nearly doubled the rounds to catastrophic failure on cyclic. An open/closed bolt cycle might have practical benefits. They wouldn’t show up in sustained heavy firing like the destruction tests, but they might show up in how a weapon recoups from high temps, and open-bolt autofire would eliminate cook-offs, at least. But any such approach needs thorough testing.

The Wrong Answer: Replacing the M4 with something like the SCAR or the HK416, something that is, at best, barely better, that is much more maintenance intensive, and that, contra Scales’s assertion that his undisclosed client’s weapon is “the same price,” is twice (SCAR) or three times (416) the money. (The 416 mags are the best part of the system, though).

It would be interesting to duplicate Jeff Windham’s M4A1 destruction tests with AKs and with other competitors, like the 416. Scales says a piston system like those (never mind that each one is a very different design) would not fail under the conditions seen at Wanat. We’ve seen from the information here, that the failure of firearms under high rates of fire is driven by the physical problems of waste heat and metallurgy. Our prediction is the laws of physics apply in Russia and Germany as well.

Did Weapons Cause Deaths at Wanat?

We’ve talked about how the weapons fail, when they fail, today. But in the previous post, we were looking at this in the context of a very important question: did weapons deficiencies cause deaths at Wanat? We reached our conclusions. In The Atlantic, Major General Scales, the undocumented lobbyist and long-retired talking head, reached the opposite conclusion, and asserted that the nine fatalities that day resulted from, specifically, M4 failures. We are not sure whether his problem is lack of familiarity with the material we’ve presented here, or whether it’s an integrity issue, but we think we’ve rather conclusively made the point that any honest answer comes back, “No.”

But it’s worth noting what the other investigations decided.

  • The historical investigation, both the Cubbison and the final, come up, “no.”
  • The RAND report does not fault the weapons. It does suggest some theoretical future weapons developments, such as miniguns or thermobaric weapons, and points out the dead-space problem without making a specific suggestion of how to address it.
  • The Army 15-6 investigation, came up “no,” and said so explicitly.
  • The DOD Inspector General investigation, that was extremely critical of the leadership of the company, battalion and brigade, did not mention weapons as a factor.

And so we’re not really in bad company, even though were on the other side of a Major General on this.

Notes

1. A good web article is about 300 words. A good newspaper column is about 700 words. Because we have faith in our readers’ ability to follow pieces of greater length and complexity, we frequently go to 1000 or even 2000 words (although our mean comes in around 600). That article was 3,129 words. And well illustrated, too.

Sources

Chivers, CJ. The Making of the Military’s Standard Arms, Part II. New York Times (online): 12 Jan 2010. Retrieved from: http://atwar.blogs.nytimes.com/2010/01/12/m4-and-m4a1-guns/?_r=1

Department of Defense. MIL-STD-3029: Department of Defense Test Method Standard: Hot Gun Cook-Off Hazards Assessment, Test and Analysis. Washington, DC: DOD, 23 July 2009. Retrieved from: http://everyspec.com/MIL-STD/MIL-STD-3000-9999/download.php?spec=MIL-STD-3029.022917.PDF

Guthrie, J. Reviewing Black Hills’ MK 262 Mod 1 Ammo. Shooting Times: 21 Mar 2012. Retrieved from: http://www.shootingtimes.com/ammo/special-forces-to-civilians-black-hills-mk-262-mod-1-review/

Hameed, Amer,  Azavedo, Mathew, and Pitcher, Philip.  Experimental investigation of a cook-off temperature in a hot barrel. Defence Technology.Volume 10, Issue 2, June 2014 (28th International Symposium on Ballistics), Pages 86–91. Retrieved from: http://www.sciencedirect.com/science/article/pii/S2214914714000385

Ross, Kirk. What Really Happened at Wanat. Proceedings Magazine, July 2010. Vol. 136/7/1.289. Retrieved from: http://www.usni.org/magazines/proceedings/2010-07/what-really-happened-wanat

Smith, Herschel. The Captain’s Journal. Multiple posts on Wanat linked to his Battle-of-Wanat category. Basically, Hersh has beaten all this ground years before (and we’ve even cited his reports here, before). Retrieved from: http://www.captainsjournal.com/category/battle-of-wanat/

Windham, Jeff. Fire To Destruction Test of 5.56mm M4A1 Carbine and M16A2 Rifle Barrels. Rock Island, IL: Engineering Support Directorate, Armament Research, Development And Engineering Center. September, 1996. Retrieved from: http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA317929  (Abstract: http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA317929).

Witherell, Mark, & Pflegl, George. Prediction of Propellant and Explosive Cook-off for the 30-mm HEI-T And Raufoss MPLD-T Round Chambered in a Hot Mk44 Barrel (Advanced Amphibious Assault Vehicle – AAAV). Watervliet, NY: Army Research Laboratory/Benet Labs, March 2001. Retrieved from: http://www.dtic.mil/dtic/tr/fulltext/u2/a388280.pdf