"Have you ever had that home improvement project that you knew your dad would have done perfectly the first time, but you keep having to do it over and over, because you didn't get the fundamentals right the first time, and the kids kept messing with your tools? That's the history of the M-16."
~Cherry
Gun Lubricant History: Vietnam, & the Great Disconnect - How "Gun Oil" Became the Norm
Early M-16 training film. Notice that despite great mechanical detail, there is ZERO mention of lubricant in the entire film. Forward to minute 10:20 to see depiction of direct impingement gas system in action.
From World War II until the middle of the Vietnam War, US military weapons were incredibly reliable - using grease was a key part of this. However, grease is largely unseen today in either the shooting or military communities for small arms, and this is a severe problem. Somewhere along the line, there was a "great disconnect" in fundamental survival knowledge on keeping guns running. In effect, we lost the knowledge of our Industrial Era ancestors - on guns. This is not the case in other fields, where basic grease vs. oil knowledge is still common, and where best practices are still actually practiced.
As best can be discerned, this great disconnect occurs during the adoption of the M-16. A combination of misunderstanding, misinformation, and mistake on the part of both those providing the weapon and those using it all came together to lead to a plague of problems. It's difficult to pin the entirety of the problem directly on one single item, but a constellation of factors comes together at this time which seems to have taken us backwards with gun lubricants.
The first major departure seems to occur with the M-16 being marketed, or at least understood in some circles, as being "space aged", with at least one manufacturer claiming it to be "self-cleaning". These ideas, the operating environment, improper
training, and surprisingly simple lubrication misunderstanding by those in authority all come together in ways to have left the importance of grease in guns lost, over the course of what became a full-fledged worst-case scenario of military procurement.
To understand how this genuine disaster unfolded requires understanding that mass industrialization, and the nature of industrialized warfare, were foundational to the Pentagon at this time. Critically, the ideas of the "best and brightest" Cold War DoD machine, specifically the "Whiz Kids" of Secretary of Defense Robert McNamara, dominated procurement. A key part of this, in many cases, was preferring cheap and easy-to-replace over high quality. This group of people, and some in the military, saw the advantages of the M-16 system over the heavier and larger caliber M-14. The M-16 was substantially cheaper to produce, in
part because it had far fewer machining steps and a less complex system in general, in addition to heavy use of cheaper synthetic materials. The M-16 also brought other advantages, including fielding twice the ammunition per pound over the M-14, being a lighter weapon in general, having light recoil, greater control during full-auto fire, simplicity in field-stripping, and several other qualities. However, the military also is by nature conservative, and the newer M-16 was small, 'plastic', didn't have the range of the M-14, and didn't have the robust feel of traditional rifles. Additionally, both the Marine Corps and US Army, especially at the time, prized marksmanship. All this combined leant great cultural emphasis to keeping the M-14. Tragically, these and other factors led to the M-16 program falling victim to exceptionally severe internal DoD politics, most notably clear and documented sabotage by the Army Ordnance Board.
Not only were evaluation tests severely sabotaged directly by tampering with early test guns in several ways, the Army Ordnance Board further attempted to indirectly delay and sabotage later M-16 trials with bureaucratically excessive changes and requirements. While some of these changes were legitimate (including chroming the chambers to prevent rust in a jungle environment), incredibly, when McNamara uncovered the sabotage via an Inspector General's report he ordered the Army, directly and explicitly, to adopt the M-16 as is, and he shut down production of the M-14 to force the conversion. This fielded a mass-produced weapon system with several shortcomings. Additionally, so severe was the Board's opposition and sabbotage of the M-16 program, that it has led some observers to be suspicious of a sudden, poorly justified switch of ammunition powders that was forced by the Army Ordnance Board - against the advice of manufacturers and the weapon's designer, Eugene Stoner. The change, from a thoroughly tested stick-shaped powder to a ball powder, radically shifted the pressure spike during firing from the beginning of fire, to a place much further down the barrel during the bullet's travel.
Robert McNamara served as SecDef under JFK and Johnson, and is credited with being the "architect" of the Vietnam War. As a former automotive exec, he placed priority on industrial theory.
This change in the pressure curve, peaking later, slammed a much faster jet of gas into the action before the brass casing had a chance to fully 'depressurize' and pull away from the wall of the chamber. This was both unseen and inconsistent in its effects, with the result being a seemingly random tendency for extractors to slip off the rim of the cartridge and cause a double-feed, sometimes break entirely, or worst of all for someone in a firefight, rip the casing's head right off, leaving the remainder of the casing stuck in the chamber. Additionally, the faster cycling battered other parts in the weapon, in some cases severely. As regards lubrication, the ball powder also added tremendous amounts of fouling, along with a faster jet of hot gas into the action, which substantially increased lubrication requirements in the M-16.
Compounding these DoD-level political problems and actual functional problems was a key marketing message: that the gun was "self-cleaning". This appears to have been told to both military and civilian end-users. The theory was that in using a small jet of gas to cycle the weapon, the direct-impingement design would 'blow carbon' out of the action. However, the tribological reality is that, unlike the Garand or Kalashnikov actions, that jet of combustion gas fired into the DI action serves to directly transport friction contaminant into such actions, with every shot - both particulate and heat. This adds friction to a design that already has a lot of friction surface. And again, to understand firearm reliability, think in terms of friction surface and friction contaminant.
Daily, detailed maintenance for the M-16 in Vietnam was an unforgiving survival reality.
At the user level, while the challenges of direct application of friction contaminant into the DI action can be overcome effectively with proper lubrication and maintenance, it is a system much less forgiving of both user error and inferior lubricant, regardless of powder or ammunition selection. This inherent design challenge was compounded by a host of other problems during the adoption of the M-16. A Congressional report from 1968 found that M-16s had not been individually issued cleaning kits or lubricant, that personnel had been using available lubricants improperly (23% had been oiling cartridges, which is a severe no-go), and exceptionally high percentages of personnel didn't receive maintenance training for the M-16. Throw in the gunpowder changes, unchromed chambers being prone to rust, and a muddy jungle environment, this adoption and fielding process saw the M-16 savaged with an incredible array of highly challenging friction contaminants, at nearly every turn. Among other things, this constellation of problems not only resulted in a rash of mis-diagnosis and misplaced blame, it also obscured the reality of what was occurring with lubricants during firing.
The problem with a lack of proper lubricant in this system cannot be overstated. While possessing great advantages in terms of accuracy and light weight, the Eugene Stoner-designed direct-impingement systems are also possibly the single harshest weapon systems ever fielded as regards lubrication. For most centerfire rifles, gas temperatures at the muzzle exceed 2000°F - it is only the exceptionally short duration of this temperature spike that keeps this extreme temperature from being obvious, but those experienced with shooting with suppressors know they can get red-hot quickly, and steel begins to turn red at about 1100°F. Suppressors trap much more of this heat than other components. On the other end of the barrel, at the rear of the gas tube, in DI systems the brief jet of gas used to cycle the action spikes around 1000°F upon
exit, and also contains carbon particulate - it would be difficult to intentionally engineer a harsher environment in a gun for lubricant. That brief jet of hot gas will both evaporate and tend to blow off improperly selected oils, especially under prolonged fire, while also tossing in raw friction contaminant. Without the proper selection of lubricant base stocks, effective heat tolerance, and a properly selected additive package of boundary lubricants, a DI system will cause a lubricant to fail quickly. The flip side to this, is that proper lubrication allows the AR design and its users to genuinely flourish under its other advantages.
Unfortunately, early on, not only did the M-16 not have lubricant optimized for its system, many personnel who were issued the rifle just didn't have lubricant for it at all, with the entire issue seeming to have been addressed in a haphazard way. Depending on the unit, individual, timeframe, training, and logistics capacities, some Soldiers and Marines ran their weapons dry, others used available field-expedient oils (including motor oil), and some units were actually issued a general lubricating and light weapons oil, VV-L-800. In February 1965, the 173rd Airborne Division became the first regular Army unit to be deployed to Vietnam with the early M-16, the XM16E1, and almost immediately problems surfaced with the reliable functioning and lubrication of it during
actual field use. And while many suffered from the misunderstandings and mistakes noted above, many of the personnel first issued the XM16E1 were in fact incredibly competent with weapons maintenance, some of whom were distinguished competition shooters and combat veterans of prior wars. In what must have felt like a Kafkaesque sense of injustice, not only was early blame for the M-16's problems placed almost entirely on those using the M-16, despite the documented early resistance to its adoption, once it was actually fielded DoD authorities - including lower-level field commanders - seem to have gone to great length to obscure the difficulties it was having in combat. However, as these early lubrication and mechanical issues came to light, it didn't take long for people back home to hear about it, and to cause a substantial stir.
By the Fall of 1965, these problems had become so commonly reported in the press, and enough constituent concern had come to the attention elected officials, that many officials began placing pressure on Washington to address reliability and lubrication problems with the M-16. This included former US Presidential candidate Mitt Romney's father, then-Governor of Michigan George Romney, who started a drive to send Christmas care packages to troops in Vietnam that included a bottle of commercially available dry lubricant, called Dri-Slide. This product used an evaporative carrier oil to apply Molybdenum Disulfide, which is essentially a flat, microscopic, incredibly slick platelet that adheres to metal surfaces, providing a boundary of lubricious material to prevent friction between bearing surfaces. Romney's efforts at meeting troop needs appear to have created demand for the product, and while not adopted by the Army, the US Marine Corps issued Dri-Slide for a brief period. This pressure continued, and in 1967 another Michigan political figure, Congressman Charles Chamberlain, participated in the special Congressional hearings on the disastrous fielding of the M-16, chaired by Congressman Richard Ichord.
Gov. George Romney, front, second from left, on a 1963 civil rights march. In 1965, Gov. Romney placed important political pressure on the DoD to solve lubrication issues plaguing the M-16.
From 1965-1968, as political and media pressure steadily mounted, the military investigated and addressed many of these early M-16 issues, including lubricants. In 1966 the pressure finally resulted in the government's Rock Island Arsenal being tasked with investigating Dri-Slide and other lubricants used in the field. Rock Island concluded VV-L-800 was more effective than Dri-Slide for the M-16 in Vietnam, and the Marine Corps ceased carrying Dri-Slide in its supply chain in 1967. The science behind this is worth noting - as is nearly universal with dry lubricants in guns, the sheer forces, friction contaminants, and other operational realities tend to neutralize the effectiveness of these lubricants fairly quickly. As a general rule, a properly designed lubricant will get synergy out simple oils and boundary lubricants - which is what most 'dry' lubricants are - by combining them, getting far better results than the sum of what either could provide independently. However, while Rock Island found VV-L-800 to be more effective in Vietnam on the M-16 than Dri-Slide, as a simple oil in general, and with its own particularly thin properties, VV-L-800 continued to provide inferior and problematic lubrication in M-16s.
It wasn't until the adoption and widespread availability of a new lubricant, called LSA, that things got a little better for the M-16, and those whose lives depended on it.
LSA: A lubricant that saved lives
Segment of the lubrication section of the Vietnam-era M-16 maintenance comic book, an innuendo-rich 1968 manual illustrated by the famous Will Eisner, designed to remedy misunderstanding and poor training expieriencd by many personnel.
LSA (Lubricant, Small Arms), while unheard of by many, has managed to maintain a small but dedicated following of users, largely from the community of Vietnam-era veterans who have experience with it. For a couple of decades before common internet access became available, many of these vets hunted for LSA at military surplus stores, as many have found that nothing has worked as well for them on their firearms. This included lubricants adopted after LSA was replaced with newer-issue lubricants.
While LSA is now easily available online, awareness of its properties has largely entered into uncommon knowledge, and it is not in high demand. As with grease, once LSA was superseded by CLP as the standard in the Department of Defense, understanding and awareness of its effectiveness disappeared from the military - which often drives civilian awareness. Culturally, LSA, like weapons grease, and many basic maintenance skills formerly acquired just as part of growing up, became forgotten. Those few who have more contemporary military experience with LSA associate it with crew-served weapons, where it's still occasionally seen, even though it remains a great all-around firearm lubricant.
LSA was the first issue lubricant to genuinely withstand the torture chamber of direct impingement actions. It was a tannish-white lubricant that came in several weights, generally presenting as a thicker 'oil' - and was even marked on the bottle as 'oil'. However, what is not commonly known is that LSA is actually a lightweight grease. Using relatively small amounts lithium stearate
thickener, LSA is what is known tribologically as 'semi-fluid grease'. This puts it around the range of a #000 NGLI consistency, somewhere between the consistency of cooking oil or a light lotion, depending on the particular formulation.
As a grease, it held up much longer than oils in the brutal lubrication environment of M-16s. Interestingly, some of its formulations apparently contained a relatively large detergent package that assisted with cleaning the substantial carbon those M-16 actions were contaminated with.
As an important side-note, balancing the additive package of a lubricant is often the most complex part of lubricant formulation. As regards detergent, there are several ways for lubricants to assist in cleaning, other than using high amounts of detergent. And as with Automatic Transmission Fluids, the drawback of some detergents and 'cleaning' additives is that they can interfere with or even eliminate the tremendous benefits of certain boundary lubricants, treating them like a contaminant and preventing them from adhering to metal surfaces. In effect, an improper mix of additives can be like having the wrong engine in your car. Worse, any oil or grease without boundary lubricants - which includes many marketed to shooters - is a job half-done. It's the tribological equivalent of trying to sell a car without a motor. It's half the product it should be. As a rule with few exceptions, not having boundary lubricants is simply improper tribology, though there are a large variety of boundary lubricants that may or may not be appropriate for a given machine. But even when the right ones are selected, low quality tribology can put together an additive package which cancels out the benefits of the different additives, and detergents are a key danger area that must be dealt with carefully. And as a general rule, if a 'gun oil' has enough detergent in it to noticeably assist with cleaning - as with LSA - it either does not have boundary lubricants, or the detergents are neutralizing their effects.
LSA, a lightweight, lithium stearate grease that was a lifesaving development for the M-16. Note that it is wrongly labeled "oil".
That said, LSA sufficiently did everything the M-16 needed a lubricant to do, some of it quite well, beginning with just staying put and surviving that harsh environment. It was a tremendous improvement over VV-L-800 and other oils, allowing for much longer periods of fire between failure, and as a grease it cleaned up well. The drawback without the use of boundary lubricants is increased wear and greater frequency of malfunction, but combined with proper training, and several modifications to the M-16, most of the weapon's core reliability problems were cleared up effectively with LSA. It provided a major leap in combat effectiveness, and in doing so, LSA, without doubt, saved lives.
The experience of the M-16 in Vietnam serves as the "Great Disconnect" in the understandings within the shooting community, that have seen us forget the survival importance of grease. Between the generally haphazard way M-16s were issued, without cleaning kits or oil, to the VV-L-800 that was eventually issued, this began the severing of those cultural understandings. When LSA was issued, the fact that it was both marked as an "oil" and could be easily mistaken as an oil by a shooter, instead of a grease, only furthers this cultural disconnect.
However, just as this M-16 lubrication problems were smoothed out by LSA, the Cold War-era DoD machine threw a tremendous lubrication hurdle into the works.
And it's arguable we haven't yet recovered.