AR 15 Bolt Carrier Group

Lube.

I am a huge fan of moly disulfide too. Plate+ is what I use from Sprinco.

The bolt of an AR is usually parked/nitrided/coated etc. Someone will chime in and tell us what they are coated with.

So just starting wet with CLP is the way to go. It will settle down after a few rounds. Then lube it from time to time.

You could sand the bottom of the bolt carrier where it slides over the hammer and treat that.

But the rest of it I would use the coating for what it is designed to do which is to hold a little oil.

The more expensive the faster

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I don't know about that. The only real thing that makes a BCG cycle faster is more gas and/or a light carrier & light buffer.

There are many good carriers, but the bolt should be a good quality. I like the PSA bolts: Made of Carpenter 158 Steel, Fully Machined 8620 Steel Extractor, Mil-Spec Manganese Phosphate Finish, MPI Tested (Marked with "M"). MP and/or HP stamped are also good.

I don't think NiB coated are worth the cost. They might be easier to clean, but I have never broke a sweat cleaning BCGs.

Just get a good quality BCG and keep it lubed. CLP is my choice.

JM Browning said:

I see where there are different bolt carrier groups, made from different types of metal. The more expensive the faster, not prone to heat, the better. I ordered some Molybdenum disulfide for some of my rifle barrels. Makes them slicker doesn't react to heat, doesn't mess with the rifling, makes it easier to clean. The bullet shmuts won't stick. Tell me if I were to apply this to my bolt carrier group will it make a differance? Colt LE 6920

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Your Colt 6920 has a very good bolt, made of Carpenter 158 that has been properly treated/high pressure tested/magnetic particle inspected, and shot peened to relieve stress. You would be hard pressed to shoot enough ammo, hard enough, to wear out the bolt.

Use enough lube (on the bolt and the exterior of the carrier) and you'll be good to go. That's it. If in doubt, use more. If you aren't sure if you are using enough lube, use more. If you think you are using too much you're good to go.

I echo Warp and would add "keep it wet" my favorite lube is 5-20 Mobil 1 dispensed in a Brownells bottle with a needle extension for hard places. Being wet the BCG will run forever and makes for really messy cleaning jobs . One place I do not lube is the rear of the bolt where the gas rings are as it will just increase carbon buildup and nothing there needs lube anyway.

Try it and see if you like it. I just use any number of good wet lubes and never have a problem. I shoot semi-auto like everyone else so I don't see any need for special treatments.

High speed bolts with exotic finishes are sold because they can be. The AR15/M16/M4 has been in use for over 45 years and a good steel BCG with a parked finish does the job. Nitriding is nice, but not necessary.

The military flirted with chromed BCG's and I never found them particularly easier to clean, they just showed more of it for the armorer to reject and send you to the back of the line.

All the special finishes are ok for a safe queen, you need them since it's never shot much and less likely to get used. Atmospheric moisture is the #1 corrosion problem with most guns anyway.

Lube it. I keep mine wetted down with a high detergent high pressure additive lubricant which has been tested to stick for at least a year even exposed to the elements. Most of the time gas blowback out of the chamber is what cooks off lube anyway, so frequent application is important. With that kind of use, an expensive oil is no better as it's not on the parts long enough to pay it's way. But Dexron for $5 a quart does a good job.

A lot more cost effective on a using gun than the latest Coating of the Month club entry.

The only thing a BCM or Colt BCG needs coated with is lube.

I've seen chrome, and the gold TiNi coatings flake off and jam the bolt into the barrel. And any gun company that says their majik coatings allow their AR15 to operate without lube, is a company I avoid.

If they say "easier to clean", I'm ok with that.
If they say "better in the event of lube drying out", I'm ok with that.

If they say "needs no lube", then they are retards right up there with the "breaking your barrel in with 1 million passes of a super hard metal brush" crowd.

Agreed with Zerodefect

Wouldn't putting moly or and other goo in a barrel count as a bore obstruction?

I always run my barrels dry, meaning I push a dry patch through the bore before shooting

The Sprinco Plate+ moly treatment can't stick to its self and build up.

But it's $$$$$. You need to soak the parts in a small container, and if you're lucky you can reuse some of it. Do all your BCG's at the same time. No idea how long it lasts, and you still need to lube regularly just like any other rifle.

I use Mobil 1 also, haven't cleaned it in 2000 rounds and went to a 2 day carbine course with it and I only lubed it once each morning. It was only about a 400-450 rd count per day though. That BCG is a BCM.

I would skip the moly...not needed and may cause issues gumming things up. If you do use it, just put some on the rails and that's it, not all over the BCG.

There's enough Mobil 1 left over in the bottom of the quart after I change the oil in my car to drain, save in a smaller bottle, and keep my ARs running happy for literally years.

No need for any kind of crazy lubes; if you don't change your own auto oil, then go buy a quart of Mobil 1 and you'll be set for you firearms lubrication for life.

I don't like it much when all my Mobile1 ends up in my buffer tube.

I mix:
ATF, STP and Lucas Red&Tacky bearing grease together until I get the thickness/stickyness I want. And refrain from the grease for a thin lube.

Makes a couple qts. Lasts forever. I pour it into hotel shampoo bottles and give it to my friends and people that forget their lube at class. I apply it with Testors brand model paint brush.

Melonited 1911's get Weaponshield or FP10. Some melonite dulls and mattes out if you get weird oils on it like most CLP's.

JM Browning said:

I have read if one uses a product not made for firearms may be a carcinogenic. I believe everything I read on the Internet, but...........

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I didn't know guns could get cancer

fulton armory has nitride bolts
http://www.fulton-armory.com/bolt-carrier-group-m16-nickle-boron-coat.aspx $170.00 plus ship

that is nickel boron coated, not nitride

I have read if one uses a product not made for firearms may be a carcinogenic. I believe everything I read on the Internet, but...........

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Any and all petroleum distillates (3in1, Mobil 1, any automobile oil, gasoline, diesel, etc.) are carcinogenic. There are a lot of things in the gun-world that can be potentially unhealthy, lead @ 3,000fps notwithstanding

You'll put your eye out!

Not to change the subject, but I really want to know after reading all the replies. What does our GI's use overseas for lube for their AR's.

I've seen pictures of my dad in 'Nam with an oil bottle under the strap on his helmet, but he has passed and I can't ask him.

I just have an M&P15 Sport.

Thanks

Mostly CLP, though different stuff has been issued at times.

Thanks.

I liked BreakFree when somebody else was buying it (thank you, taxpayers) and used it for a while on my own dime. Then I discovered 50/50 mix of motor oil and tranny fluid. My rifles seem to run very well with it and it's FAR less expensive than buying gun specific lubes.

Ibmikey said:

One place I do not lube is the rear of the bolt where the gas rings are as it will just increase carbon buildup and nothing there needs lube anyway.

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That is actually the most important place to lube. It reduces friction between the bolt and carrier and the oil keeps the carbon fouling soft for easier cleanup. Just place a few drops of oil in the exhaust ports. The carrier actually floats inside the upper and lube there is useful but not as critical