I have heard of these being used when building an AR. I have just started building my first AR and was wondering where you would use these. I can see the loctite on the pistol grip screw and maybe the buffer tube castle nut but is there anywhere else you would want to use these?
Loctite on optic mount screws and such…but nowhere on the assembly of the actual weapon.
Moly grease on the castle nut…quite the opposite of loctite! Moly grease on the barrel nut as well.
I’m thinking you should sit on your parts for a while and read some…
Light moly grease on receiver extension threads/castle nut. Torque to 35-39 foot pounds pounds three times(loosening after the first two) and stake receiver plate into castle nut.
Light moly grease on barrel nut and torque to 30 foot pounds several times and then torque to the next gap so that the gas tube passes through without exceeding 80 foot pounds.
Flash hider gets a crush washer and 30 foot pounds ONCE as the crush washer is one time use.
No effing loctite on any of those components…
ETA:Loctite is fine on the pistol grip screw…though in my experience a locking washer does just as well, ditto on ambi safeties and as Kenneth said, things that go on the rail.
I used blue loctite on anything that gets attached to the rail or flat top reciever. On the pistol grip screw and a drop on the Battle Arms safety lever. I used anti seize on the barrel nut.
Foot pounds. The 40 in-lbs is a typo and is nowhere near proper torque. Come on guys, think about it. Does <3.5 ft-lbs seem like a good amount of torque for a nut on a semi-auto rifle?
Absolutely right…35-39 foot pounds.
thopkins22, you are the second person to say the same thing about not using the loctite. Can you explain why this is a bad idea so that anyone who reads this will know? And also do you have a preference of brand of moly grease?
Put some loctite on the threads of your loctite cap. Then stake the cap, and throw the stuff away.
I don’t own any loctite and I put a fair amount of guns together.
It’s a good idea to apply blue Loctite on the screws that hold together your rail/handguard, too. All the screws that get Loctite should have witness marks. No place for red Loctite on an AR.
The grip screw doesn’t really need it since it has a lock washer.
Castle nut needs to be staked, not Loctited. Do a search; this has been discussed a lot already.
The only place I use loctite is red on low profile gas block set screws.
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Red Loctite is only good up to around 500° F. Rocksett is a better choice for gas block screws and muzzle devices.
Great post. I laughed out loud when I read this. 
Using Loc-tite is a good thing and a bad thing. When it is applied in the correct way it’s great, and when applied improperly (castle nut, barrel nut, etc…) then it’s a bad thing.
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Castle nut- Anti-seize or grease. Tighten the nut and stake it.
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Barrel nut- Torque the nut to the correct spec and then finish the install.
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Screws- If you are planning on removing them at some point without massive effort then generally you should use blue Loc-tite. I use it in mounts, rail screws, etc… On the gas block I use high strength red Loc-tite. If they are screws for securing the rail like the Troy VTAC you can consider red as well. I don’t put them on USGI grip screws and it’s been my experience it isn’t needed when using a proper lock washer.
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BCG- This is a matter of debate, but I generally will apply red Loc-tite and then stake it with a MOACKS.
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Copper or no copper? Graphite or no graphite? Does it matter at all?
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Only Moly Disulfide lube here?
Ned Christiansen is working on a LOCTITE MOACKS. :sarcastic:
what about urx rails ?
I use Loctite for certain applications and Anti-seize on the barrel nut instead of grease. Of course the application of Loctite requires some measure of intelligence and the know how to undo it when the time comes.
The only place on an AR that “officially” sees Loctite is on an A1/A2 buttplate screw.
These screws come with the crap pre-applied and we usually try to scrape most of it off so the screw can be installed.
There are aftermarket parts that may call for Loctite.
If you look at the TM(s) most all of the threaded connections call for moly grease.
Aero Shell 33MS meets the specification and there are other greases that are similar such as Valvoline VV632
Our torque specs are assumed to be “wet” so using grease is important for that, preventing thread galling and separating dissimilar metals.
ARs have been assembled with everything from nothing to KY jelly.
Use whatever floats your boat.
Copper is fine but no graphite, as it can cause corrosion over time. As said, use aeroshell MS33. Meets the mil-spec for working on AR’s.
Actually anything that is a conductor (copper, aluminum, graphite, etc) can enhance/accelerate galvanic corrosion.
In a military weapon that could see a corrosive environment this is a consideration.
In a hobby gun, not so much of a concern.
I can’t believe I never made that connection (conductivity) between those two as lubricity agents before, and why they wouldn’t be recommended. In my research, there are a lot of sites that will poo-poo one and praise the other, but never be on the same side of the argument (This site not included) and definitely no explanation as to the “why” of it. Though, after hearing the “why” it seems obvious, and I feel dumb.