AR-15 Grease

[Beren]

Well, I hope I didn't just commit a mortal sin. I had a previously assembled Bushmaster lower receiver to which I attached a buffer assembly and ACE skeleton stock.

I didn't have any "real" gun grease, but I found some black moly grease and used that on the threads for the buffer tube, spring, and the two pins/springs. I think the grease was graphite based, but I'm not sure.

Was this a bad idea and should I plan on tearing the whole thing apart?

I should have asked prior to assembling! The impatience of youth.

 

[Zak Smith]

I don't bother to grease the threads screwing the buffer tube (aka receiver extension) into the receiver. If I'm not going to disassemble it again for a while, I'll lock-tite it.

I have no idea what you're supposed to put on those tiny springs. I usually just rub some CLP on thme before installation.

I like to run my operating springs & buffer dry. Some people like some light grease in there to avoid the "SPROING" sound, but remember that lube will collect dirt.

-z

 

[Chris Rhines]

I put a dab of anti-seize on the buffer tube threads and barrel nut threads, but really almost any grease will do in a pinch.

- Chris

 

[JNewell]

Moly grease is fine on the threads. It's too heavy for the springs to function as designed. They should be lubed with something lighter, like CLP.

If the grease has graphite in it, you may need to disassemble, clean and reassemble. Graphite can cause galvanic corrosion of aluminum.

 

[Beren]

I was afraid that might be the case. How may I determine whether or not the grease contains graphite? All I know is that it's black. The only label on the tube said "moly grease."

 

[JNewell]

Short of an assay, I have no idea if the container doesn't say. Can you check the manufacturer's website for literature or an MSDS?

 

[Beren]

Unfortunately, it's an unmarked tube that was originally, I believe, meant for use on electronics.

 

[Badger Arms]

I always grease the face of the hammer and contact surface on the bolt carrier. Not sure if it needs it, but I do it anyhow. There's really no need for grease anywhere else as far as FUNCTION goes, but for peace of mind, you can grease the shiny contact surfaces of the bolt carrier and also cam pin and camway. Tetra Grease doesn't seem to attract dust or debris in my experience.

 

[Beren]

So is this my bottom line:

If I wish to best protect my $300 BM lower receiver and the $85 ACE stock, I should disassemble, degrease thoroughly, and grease properly with a $4 tube of Tetra?

I also put the suspect grease on the buffer spring..and in the holes for the two pins. All that has to come off/out...?

What's the best stuff to use to get all the grease out? Brake fluid?

Will the act of removing all this grease cause more harm than leaving it in place?

 

[JNewell]

If you think it may have graphite in it, yes, I think it would be prudent to strip the grease thoroughly. If it does have graphite in it and you get corrosion on the threads, you will be kicking yourself for a long time.

I wouldn't use brake fluid. I'd use something that will really evaporate, maybe benzene or mineral spirits, if MS will cut the grease. In a pinch, I'd use gasoline (not first choice).

 

[Badger Arms]

I've found that the best way to degrease is to drop all the parts into a METAL bucket with some gasoline and scrub the heck out of it with toothbrushes. When you're done, all you have to oil are the metal parts. Don't go hog wild with the grease, the AR-15 will function just fine with light lube on the bolt carrier assembly only. I put a CLP moistened patch wedged into the rear coil of my recoil spring to get rid of the Sproing. A dab of CLP or Tetra Lube on the detent springs, ejection port cover detent, sight adjusting detents, and bolt handle locking recess. One drop on each side of the trigger and hammer pins. You're set.

 

[Beren]

Thanks for all the advice, folks. I finally got in touch with my father today - he supplied the grease. He says he's "pretty sure" there is no graphite in it. I'll reinspect the tube this weekend, but I may have dodged one here. Learned my lesson, though - don't be so darned lazy, Beren, just drive out to WalMart if you must and get stuff you know is right!

I may just degrease anyway - just to be sure. Getting it out of the detent spring housing is going to be a chore.

 

[JNewell]

What are the chances worth? Might be harmless...might be that in five years you take it apart and find the threads are corroded and the aluminum has been structurally weakened? Hard to say...better to play it safe?

Getting it out of the detent spring housing is going to be a chore.

Hose it out with something like carb cleaner (make sure it's plastic-safe). I would be a lot more worried about the threads on the buttstock/receiver extension, especially if you're only "pretty sure" it is graphite-free.

 

[BrokenPaw]

For what it's worth, if the grease was originally intended to be used on electronics, the chances that it has graphite in it are very small. Graphite conducts electricity, and smearing a graphite-bearing grease onto anything electronic is pretty much destined to cause heartache.

So I wouldn't worry about graphite.

-BP

 

[Don of Kalifornia]

Get a couple of cans of brake clean, non-chlorinated. be very careful on plastic as heavy use on plastic will damage it,light use ok. you can get it at most chain autopart stores from around $2 a can, I buy it buy the case for $10-$12 a case. Most cans have a nice little spray straw attached to them, works real well to clean out blind holes, just be sure to use safety glasses. After cleaning out any holes blow out hole with some air.

Brake clean totally strips all oil from what ever it touchs so relube as soon as possable. Don't ever, ever clean anything with gasoline as the fire hazard is very fire, also the chemical make up of gasoline will damage many finishes and plastics. Gasoline also leaves very nasty residues behing.