Would Mil Comm MC1210 lithium grease be good for installing a barrel nut? I'm a little confused about all the different opinions out there on which brand is the best. Most people recommend lithium grease, and MC seems to make the best one on the market.

The barrel nut needs an assembly grease, not a lubricating grease.  The Mil-Com grease is a great lube, but it's not an assembly grease.

Can you explain the difference? What ingredients should I be looking for in an assembly grease? What specific one do you use?

Aeroshell 33MS, I believe is what is recommended but I think I have read that  moly greases will work. If I'm wrong on the moly someone will correct me.
Here is some for sale on the EE. link

Regular grease is formulated to provide support for moving parts, allowing them to slide easily on each other.  Assembly grease facilitates assembly by spreading out forces.  MIL-G 21164 compliant greases, called for in the TM (I use AeroShell 33MS), provide a layer of known viscosity that allows you to assemble the barrel nut on the upper and apply the specified torque within known parameters.  There are other materials that work and meet specs as well, but they're all assembly greases.  One is Dow's Molykote G-N, which is apparently used in current Colt manufacturing processes.

This.

http://www.ebay.com/itm/AeroShell-Grease-33MS-Mil-spec-Moly-Barrel-Nut-Grease-by-the-jar-5-56-223-AR-/201226328606?var=&hash=item2eda061a1e&vxp=mtr

I ordered 6 small 5ml jars, so far I have only used 3/4 of 1 jar for 3 builds, and I didn't use it sparingly either

I've definitely learned a few things. Thanks.

So all the people who use lithium grease are wrong? Or are there assembly greases that use lithium?

Oh, and do I want to use the same grease on the buffer tube threads?

Use anti-seize paste.  One small tube will last you years.  Just apply one small drop to the threads, spread around, and then put on the barrel nut.

And I've been using lithium grease this whole time.  

There is some vendors that sell aeroshell on ebay as well for all my fellow cheap asses.

 The commonly recommended moly greases, e.g., Aeroshell 33MS, are intended for anti-seize duty, but have a special added feature, resistance to years of high heat.  An anti-seize paste intended for plumbing pipes, for example, would not be ideal on an AR rifle barrel nut. - CW

If I said "they are wrong," I'd be labeled an AeroShell elitist and a hater.  I think they are misguided - going cheap on anything to do with a build you're spending money on seems to me to be a real lame move - but I'm not going to ask "them" to label me as an elitist hater.  Not again.  

Yes, the receiver extension's threads get the same grease as the barrel nut.

Well, you can count on me to be on your side. Anything worth doing is worth doing right, costs be damned. I'm one of those people who thinks "good enough" equals a serious character flaw. I wouldn't trust a "good enougher" to shine my boots. If that makes me an elitist, then so be it

Oh, and I did take a look at Aeroshell 33. It contains lithium and molybdenum.

Ok. so now that I've read this thread and did some more research I'm super paranoid.

Of my toys I built 2 out of 3.  

The 2 I built are going to be disassembled at the barrel and I'll be using Aeroshell 33MS on the threads.

However, what is the detriment to using white lithium grease?  Just future proofing and corrosion resistance?

Now I'm paranoid that I should take my 5.56 upper apart because I have no idea what the jackass that put it together used on the barrel nut.

If you didn't use a MIL-G 21164 compliant grease on your barrel nut, you rifle isn't going to rot to pieces.  But the torque you applied to the nut won't be "right" due to the different viscosity of whatever you used.  And it's not necessarily going to come apart as easily as it might if you'd used the right stuff.  (Not that the grease is actually supposed to make it easier to disassemble the barrel nut, but it doesn't hurt.)

If you used simple white lithium grease on that build, you don't "need" to take it apart.  But if you have any reason to take it apart, I'd clean out the old stuff and use AeroShell 33MS on it when you put it back together.

So is it the molybdenum that makes it an assembly grease?

It's the whole formulation.  The base grease, the percentage of molybdenum disulfide, all the other ingredients.  It is slippery goo, but it doesn't have a bunch of stuff in it that makes it stay slippery, or that aids with moving parts moving.

I'm puzzled by the term "assembly grease".  To me, that implies the kind of oil or grease you put on a crankshaft before it is laid to rest on its bearings.  Its a temporary lube to protect bearing surfaces until ordinary motor oil etc starts flowing, see link below.  

Anti-seize grease, e.g., 33MS and other molybdenum disulfide formulations, however, is quite different.  The moly provides excellent lubrication under heat and pressure, as in tight threads, while the base grease is a type that resists drying out over time, its duty cycle is not temporary. - CW

http://www.royalpurpleconsumer.com/products/max-tuff-synthetic-assembly-lubricant/

With a  torque range of 30-80ft/lbs don't really think you need to worry about your torque value being "right".

AreoShell 33MS is not an assembly grease. It is a high pressure lube grease for sliding metal parts under extreme pressure such as the pivot pins on aircraft landing gear (one its primary uses).



 

MIL-G-21164 spec grease is used as an assembly grease for the fasteners on aircraft brakes, and on helicopter rotor blade fasteners, as other examples of its primary aviation uses.

The barrel nut isn't supposed to have any movement once installed, so it doesn't need grease to smooth movement.  But it does need a material that allows the dissimilar metals of the barrel nut and upper receiver to be fastened smoothly without galling.

I don't care if you or anyone else uses peanut butter on your barrel nuts, but the OP's question was about using a purely lubricity-based grease for barrel nuts, which led to the discussion of what grease is specified in tech data for barrel nut installation.  I, for one, have tried to demonstrate some of the rationale behind the use of such greases.  But maybe the folks that have been responsible for maintaining M16-family weapons since they were originally adopted have been doing it wrong all these years, and it doesn't matter if you use the inexpensive, available, and time-tested grease the tech data calls for.  Maybe garage AR builders know better than the weapon systems managers what works in the long term.

"Weapons system managers" who are visited regularly by sales staff looking for government contracts. Said managers approved a set of tools for assembly that have been proven unnecessary for the AR - a pair of taped up vice grips, some old drill bits for punches, and a large pair of Channelocks to tighten the barrel nut will get er done.

Barrel nuts are subject to high heat and the electrolysis of the aluminum and steel in close contact. Nonetheless most shooters don't stress them much, and the ones issued 45 years ago to the Vietnamese pop up still working.

For a worst case view of what could happen, take a long look at your alloy wheels bolted to the steel hubs on your car. After ten years of wet weather, road salt, etc, there's some discoloration on the back side wheire they were not clear coated, greased, or even cleaned for years. Bare aluminum against rusty steel.

Not a big deal and you put your family into the car with just 20 to 30 lug nuts holding them on. That's a 2,500 to 4,200 hundred pound vehicle getting panic braked at 70mph on the rare day. So, what a "weapons system manager" was convinced by his buddy the vendor to include in the specs means very little to me. Use something and it's covered.

As said Colt - the contract vendor - assemblies with something different than what others are selling. The internet is often a locker room measuring contest with the biggest declaring himself the winner.

Use whatever you want.  You've got free will.  Rub bacon fat on there if it makes you happy.  You're only risking sixty bucks worth of parts if you're wrong.  Seriously, it's an upper, and maybe a barrel nut.  

I'll stick with Aeroshell.  It meets the spec in the manual, it's cheap enough, and readily available in the little tubs.  It's one less thing to worry about.  And hopefully, if I need to take that upper apart later, it'll actually come apart, and not ruin the threads.  Will some other grease work?  Maybe.  Try it and let us know.

Not too much real experience with how weapon system managers work, eh?  That's just fine.

Direct from Shell:

 

Note: "used as" an assembly grease does not equate to "manufacturer's intended use."  Does a barrel nut need lubrication to move freely once it's installed?  No.  But it does need some sort of material that allows for smooth assembly of the parts, which allows for effective torquing of the nut.  That may be why it's used on aircraft brake stacks and helicopter rotor mounts.  AeroShell 33MS is used in a LOT of applications, and it works for both the lubrication AND assembly roles.  So do ALL MIL-G-21164 spec greases.  And that's why it's spec'd for use on the M16 family: it works for that job and it's in the supply system.

Seriously, spit on the nut for all I care.  But the specified type of grease does what it's supposed to, and it isn't a challenge to find.  Why so many people will spend hundreds of dollars for a barrel and almost as much on a bolt carrier group to go in their expensive billet upper receiver, and then look for the cheapest grease to assemble the nut onto the upper with is beyond me.

But that's not what you posed here many times,




















Shall I go on?
Now this last highlighted part of your post is just 100% wrong, would you not agree that your statement here does not match the properties of AreoShell 33MS or the properties called for by MIL-G-21164D?
Let me again point out part of paragraph 6.1 in the spec, "where molybdenum disulfide will prevent or delay seizure in the event of inadequate lubrication."
That sound a lot to me like it does indeed have a bunch of stuff that makes it stay slippery and that aids with moving parts moving. That is it's very purpose and reason for it's  formula. It is also one of the primary specs called out in MIL-G-21164D.
The TM calls for it for the simple reason that the military uses it and has it in stock by the ton. It will do the job so it is called out for. Not because it is the best for the job and certainly not for any of the reasons you have outlined in this thread, but simply because it is a good quality grease that is already stocked and serves the purpose, nothing more, nothing less.
 

Maybe Aeroshell is overkill.  Maybe the military ONLY chose it because they knew they'd have a ton of it in the supply chain.  Does that matter to me?  Nope.  I'm not an expert on grease.  I'm not reinventing the wheel just to save a few bucks.  Aeroshell gets my vote.

Out of context, it looks like I've said different things.  Context is important.  AS USED, the various materials used for barrel nuts are "assembly greases" because the nut isn't going to do any repetitive movement.  If you used Crisco on it, the Crisco would functionally be an assembly grease.  The application is what makes it an assembly grease.  Molykote is made AS an assembly paste, according to Dow.

What I quoted was very much 100% in context. This is a technical forum. Your statements were not based in fact or technically correct in any context.



Nothing personal, just trying to keep it technically correct.
Dow has many products in the Molykote family. The one you posted is called out as an assembly paste, but it is formulated as such and it is not MIL-G-21164 certified nor would it meet the specs to be certified, so whats your point?
eta: for the record I use AeroShell 17, which is MIL-G-21164 compliant, not because it's called for in any TM, but because I have a 5 gallon can of it under my gun bench. Got it from my days working helicopters.
 

Please point out the "technically correct" side of what I posted, and I will use that information to learn and improve.  I will point out that each of those items you quoted was selected without the context in which it was posted - THAT context is important.  Please point out the exact flaws in what I posted, given the posts I was responding to.  Provide authoritative references for all of it, since obviously there's no way to simply believe what people say on the Internet.  Much of what I have posted is my understanding of how things work together; if you can educate me on how my understanding is incorrect, I welcome it.

I have a 23+ year history of adhering to technical data, including several years as Chief of Quality Assurance over landing systems and Air Traffic Control communications systems, and about half of my career was spent instructing others in how to use such data, including providing rationales for various technical issues through synthesis of the basic tech data with other authoritative information.  Often, my explanations had to be worded both in my specific academic setting and in a way that my students would be able to apply.  Unlike many instructors, I was able to avoid "dumbing down" my material, and instead "smartened up" my students.  

Further, I worked with Air Force-level system managers and career field managers on this sort of technical material (though in the electronics field rather than weapons maintenance).  I have what could be called "from the horse's mouth" experience in this area, and I have felt that others have taken cheap shots at both my statements and the overall integrity of people who have spent decades serving our country while working hard at supporting the weapon systems our warfighters use on a daily basis.  Unfortunately, this latter part made my mood in participating in this thread less objective and more reactive, and thus decreased my attention to wording and detail.  While I welcome authoritative corrections, cheap shots are a different thing.

As for MolyKote, it appears that current Colt factory assembly instructions call for use of MolyKote G-N for barrel nut assembly.  No, I don't have a copy of that information, and the ARFCOM member who pointed it out was unwilling to publish it, since it appears to be Colt's proprietary information.  That's the only reason I mentioned MolyKote.  Since there seems to be a barrel nut grease thread started here every other day, and since you pounced on what you perceived as flaws in my technical information, I sort of felt you were keeping up with this stuff.  Further, Shell says that AeroShell 33MS supersedes AeroShell 17.  Both are MIL-G-21164 compliant.

To everyone else, use whatever you want.  I sort of feel that if it's been working since the 1960s, using a MIL-G-21164 grease for barrel nut assembly is probably a good idea.  Enjoy.  I sort of look forward to your posting your experiences with whatever you use...

I would certainly hope ShellAero 33 supersedes ShellAreo 17. My 5 gallon can is from 1983, the year I left aviation. I've assembled hundreds of rifles and used it for a thousand different jobs and the can is still full.





I think you mean for me to point out your technically incorrect side of what you posted not the" technically correct side" as you posted.


And I already did that in my last post on the first page. Nothing was taken out of context. Everything you posted was in the context of the thread but if you insist:



1. The barrel nut does not need and assembly grease. As per the TM you like to reference it is installed using a lubricating grease.


2. A layer of know viscosity to apply the correct torque? Please with a range of 30-80ft/lbs butter would allow the correct torque range.


3. None of the greases that meet the mil-spec are assembly greases.The spec calls for lubricating grease as I have already pointed out and linked to.


4. Dow MolyKote G-N is NOT MIL-G-21164 compliant. Never has been, never will be.





Let's continue:



 

1.The torque won't be right due to the different viscosity of whatever
you used is pure BS. Again the range is 30-80ft/lbs. I'll wager (95% of
everyone reading this forum can hit that range with any type of
lubricant and most likely with none at all.
2. You would clean it and use AeroShell 33 because your a AreoShell elitist. ( sorry comic relief)




1. this is pure BS also. You and this whole thread is in relation to AreoShell 33.



(A) is not an assembly grease.



(B) Does by it's very design have a bunch of stuff in it that makes it
stay slippery,
or that aids with moving parts moving. The moly itself is added to stay
and help prevent seizure in the event of inadequate lubrication. (as
specified in the mil-spec)
I won't continue. Most of your other posts are a backpeddling after I posted my response and links.



You start to claim that you are talking about "using them for assembly"
as opposed to them "being assembly grease" which clearly based on your
early posts, presented here in full context, is backpeddeling to cover
your ass.
Your premise of why a lubricant is needed is basically correct but your
misuse of term and lack of knowledge of the actual MIL-G-21164
specification, the products meeting that spec and their primary use(s)
remove all credibility from your posts on this matter.
I hope you have indeed learned something about this from the links I
posted and the actual specification itself. We are all here to learn.
But lets not simply regurgitate old internet misinformation. The
military uses it simply because it does meet their needs and it is in
the supply system in great quantities. But that does not
make it the best product for the job. Being from a military background
you should know better than a lot of people just how true that is.
I'm not trying to take cheap shots at you. You say you are able to avoid dumbing down and instead you strive to smarten up your students. But in this case the OP asked about a very viable alternative to use in the assembly. In reality the Mil-Comm product is every bit as good, or better, to use as the Mil-spec stuff.  I understand in a military setting that the mil-spec is pushed for a reason. But this is not military and the world does not begin and end with mil-spec.



From your first few posts you had the OP, as well as a couple other people, feeling like every thing they did was wrong. You effectively "dumbed them down" to a military only point of view. Even to the point of thinking that AeroShell is simply an assembly grease as specified by MIL-G-21164. That is simply not true. That is why I started my postings.



If you wish to use a MIL-G-21164 compliant grease then by all means do so. It is time tested to work just fine. However that does not mean it is the best or only thing that should be used. If your statement about Colt's use of MolyKote is true then even Colt has decided that there is other perfectly acceptable products to use that are not MIL-G-21164 compliant.





If I caused you any hard feelings I am sorry, it is/was not my intention.




 

So what I'm getting is that the specs were developed while using Aeroshell, so to repeat those specs you have to use Aeroshell? That actually makes perfect sense.

No, the specs were developed using MIL-G-21164 grease.  AeroShell's grease is ONE OF MANY greases that meet MIL-G-21164 requirements.  Choose your own maker's product.  Two other commercial products are Royco 64 and Castrol's Braycote 664.

The torque would be different at the bottom and top ends of the range with a grease that has a different viscosity.  You should know that.  Whether the torque range is 30-80, 3-4 or 0-100, that is true.  Would someone using a cheap beam-type wrench be able to measure that difference?  Probably not.  But the spec was based on the use of a grease with the viscosity called out in the MIL-G spec.  And I'd clean it off and use ANY MIL-G-21164 grease, but the discussion had brought up AeroShell 33MS, so I used that.

My attempt at addressing the "application" as an assembly grease went pretty wrong in the post you quote.  I was thinking about two different things and messed them both up. I had just been researching the use of MolyKote G-N, and didn't shift gears properly.  By the time I realized what I'd posted, the thread had progressed far enough that I didn't bother to change it.

However, there is a difference between "backpedaling" and "restating," or "correcting myself."  Maybe I don't do that very well here.  And whether or not I did a good job at correcting or restating, I was not "covering my ass."  Trying to get a concept across is more difficult when you're using text and not face to face.  But making it sound like I intentionally mislead people was WAY off base.  When I goof, I try to make it right.  I goof from time to time, and I do my best to fix it.  But when you and others essentially called me a liar or a fool, rather than having specific facts to call out as incorrect or poorly stated, it made it harder to correct my facts, or my wording.  Hint: if you address anyone's facts, you get your point made much more easily than if you attack the person himself.  That's Tact 101.

I have read the spec for MIL-G-21164 many times.  I have compared and contrasted both the qualities and content of these greases to Honda's Moly 60 paste and to many other non-MIL-G-21164 greases using that spec, posting such information here in this forum.  The idea that there are specific materials that are designed to be used specifically to simplify assembly was, however, new to me.  Since I'm not a machinist nor an aviation mechanic (23 years in electronics in the Air Force), I was not sure whether this concept would be a better way to explain this particular application of MIL-G-21164 grease to others with different backgrounds.  Obviously it's not a broadly known concept, and it certainly didn't help in my explanations.  It was not and example of my ignorance here, but lack of useful and productive feedback.  I wasn't getting across what I was trying to say, and I wasn't getting information back that said "that's not working."  I communicate; it's part of my personality.  When it doesn't work I get frustrated.  But when someone attacks me personally, accusing me of being stupid or worse, just because my attempts to get a point across don't work, that's not frustrating.  It's something different.

I don't believe I EVER said that one particular product was "the best, no contest, no other will do anywhere near as well" in talking about barrel nut greases.  I am well aware that any government acquired item is a compromise between cost, availability, functionality and safety (among other things).  But using MIL-G-21164 grease as called out in the TM makes sense from a number of directions.  It's available, cheap, easy to use, and pretty goof proof.  And it has a generational-long track record of working.  There is no other available material that has anywhere near the history of use in this application.  If this material is still doing a good job 50 years down the road, why try something else?

As I stated in my last post I was not personally attacking you. If you feel that way as a result of my responses  I apologize. This is a technical forum and it should be technically correct.
However I will point out that it was I that posted all the links in support of my claims. You might have at least posted a link to the TM that you refer to as your source.(yes I know what it says) My posts and links were as much for the benefit of the other readers as in support of my position
I do also believe the 30-80ft/lbs is a Colt specification in the TDP, long before the Mil-spec came out, although I have no link to the TDP.


But in response to your post that AeroShell 33MS replaced AreoShell 17, please note that AreoShell 33MS is now AreoShell 64 (link page 15)
We come from the same background, I was a Naval Aviation Avionics Tech on the Kaman SH-2F Seasprite , and Sikorsky SH-3 Sea King Helicopter. I also greased many a main and tail rotor in my day. After active duty I worked Navy contracts with Grumman, Harris and Burnside-Ott.

 
 

And you can lubricate all you want with any Moly grease.  It works great on steel.  It works great as a compression grease between a steel barrel nut and aluminum interface.  Something I don't see pointed out is that if you LUBRICATE a steel to aluminum interface for articulation, the Molybdenum works essentially as a cheese grater.  Whats more these days if you have intact anodizing that will probably protect you as much as the Moly grease.  You may not get valid torque values when you assemble.  


GHPorter has dished a lot of solid advice on the matter.  The context may not be as technically written as some would like(i find it fairly thought out), but it generally works out to be good solid working advice.  Anybody would do well to look at and pay attention to his complete body of advice given on here as opposed to nit picking the wording of a particular post or two.  




Not meant as an attack, just matter of fact.  


 

EDIT: I use Honda pro moly 60 on every gun I have assembled.  None have exploded yet.  Is it better or worse than aeroshell or the earlier mentioned antisieze?  I don't know.  I know it is closer to the aeroshell than the antisieze.  I know that for the most part my anodizing was always intact that I could tell.  I have some very nice shooting guns that to date still function.  IF I ever run out of Honda I may replace with aeroshell.  

The TM is hosted on the Manuals page of ARFCOM.

Pages 3-39 through 3-41 discuss assembling the barrel nut with the delta ring components and then attaching the barrel assembly to the upper receiver.  These pages mention "apply molybdenum disulfide grease to the threads of the barrel nut before assembly" (page 3-39) and "apply molybdenum disulfide grease to the <upper receiver> threads before assembly" (page 3-40), as well as the technique of tighten/loosen three times (page 3-41).

The only molybdenum disulfide grease mentioned in the TM is "Grease, Molybdenum Disulfide: (81349) MIL-G-21164 (this is on page D-3).

While there are several versions of TM 9-1005-319-23&P available online, the ARFCOM-hosted edition is dated May, 1991.  It is pretty close to the most current version available online.

The Important Threads listing at the top of the Build it Yourself forum threads has a link to "Assemble Your Own Guides," which in turn has a link to the TM.  It's highly encouraged that builders, new and old, familiarize themselves with this Technical Manual.  While it doesn't have any information on aftermarket and upgrade parts and accessories, it is the best, most thorough set of instructions for building and maintaining a basic AR-type rifle.

Okay, so now I'm going to throw a huge wrench into this topic.

I just got an Vltor VIS upper. So I called up Vltor to see how they install their barrels. They use LPS Premium Copper Anti-Seize. And they only torque to 40 foot pounds max.

Excellent! thank you.



 

LOL. I personally would steer clear of the copper.  Copper is much more noble than aluminum or steel and in the presents of an electrolyte will set up a electrochemical process known as galvanic corrosion with the aluminum being the first to go. Water (unless pure), rain(acidic), sweat, soda, lemonade, salt water/spray....all  makes a fine electrolyte. The further apart on the nobility scale the greater and quicker the reaction. Although it can happen between the aluminum and steel, the difference in nobility between the two is much less and would need a greater amount of time and/or a stronger electrolyte solution to see results. Copper and aluminum with coca-cola as an electrolyte makes a dandy battery!
So just don't spill your coke on that Vltor!
eta: this is also the reason you should stay away from graphite based grease also. Graphite is a very noble material.
 

My armorer instructor uses a copper-bearing antisieze compound too.  It is one of the things I politely disagreed with him on.  On the other hand, manufacturers warrant their weapons, so if their stuff doesn't work to keep the barrel nut from seeming like it's been welded to the upper, you do have an option - call their warranty department.

VLTOR's VIS uses a proprietary barrel nut.  There's an important point here: if it ain't a standard barrel nut, the "rules" can often go out the window.  Follow manufacturer's instructions for third-party and aftermarket barrel nuts.  In some cases, these non-standard nuts are made from aluminum, or have some coating other than the phosphate used on standard barrel nuts.  And to reinforce an important point, follow the manufacturer's instructions and let them warrant the stuff.

Vltor, really called Abrams Airborne Manufacturing, supplies a ton of weapons to the military. I'm pretty sure if there was any risk of galvanic corrosion they wouldn't use it. Maybe LPS doesn't carry that risk for whatever reason?

The science doesn't lie.



 

I think barrel nut grease threads are some of the oat entertaining.

It is WAY overblown on the seriousness of aeroshell or nothing type opinions. More so than any other type of common threads I see on arfcom.

I use a valvoline moly fortified multi-purpose grease because it was in the garage and I'm 100% confident that it can serve the same purpose without ill effects.

How the viscosity of grease will affect the torque value is silly when you are dealing with a 50ft lb range. I highly doubt the differences are even measurable in the ft lb range between the types of grease people use.

Molybdenum Disulphide is among other things a friction modifier and adding more of it to a grease lowers the torque required for the same clamping force.
There is a formula floating around the net to calculate the change for the curious.

I use Valvoline VV632.

As far as I can find there is no graphite in it at least.
If it is certified for aviation use that would be in its favor.
I have found talking to tech support or CS people does not always give a true picture.
From my perspective the mil-spec grease is relatively cheap, readily available, and very well proven.
Why be a beta tester?

This is slightly off-topic, but there are some hilarious reviews on this stuff!

http://www.amazon.com/AeroShell-Extreme-Pressure-Grease-MIL-21164D/dp/B00FSD37CM

I really have no choice but to use the LPS. That's what Vltor got the their torque specs from. If I switch to grease, then my torque specs would probably have to go up. Again, Vltor recommends 40 foot pounds.

I'm not too worried about it. LPS doesn't have any graphite, and it has something called an aluminum complex, which I'm guessing is something to cancel out the potential for galvanic corrosion. I called Vltor, and this is what they use on everything they send to the military. Keep in mind that they supply all of Army and Marine SOF with grenade launchers, and many of those will inevitably be used in salt water environments, at least during training. The Marines for sure have taken them underwater, as Recon Marines are all required to train with scuba equipment. I believe they are also required to jump into the ocean. If there was any risk of galvanic corrosion, then I think that the Marine SOF guys would have found out about it. This isn't anything new, either. They told me this is what they've been using for years.

The requirements in the TM apply only to the M16-family, "M-series" weapons, not to specialized, limited procurement weapons like those made by VLTOR for military use.  And since the TM only addresses GI weapons with standardized, issued parts, I wouldn't even consider changing anything on your VLTOR rifle.