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Dave_M
08-30-10, 23:24
Troglodyte Maintenance for the AR-15/M-16
by David Merrill and Rick Hartfield

I will preface this with this: I assume that you are not a certified Colt armorer or educated gunsmith. If you are, this really isn’t for you as you have plenty of gauges and tools and background to quickly identify problems as they crop up. This is a guideline for the average user who utilizes an AR-15 as a fighting gun. While the term, ‘troglodyte’ may be somewhat offensive to some, I don’t care because I think it’s funny.

Whenever possible, we want to ensure that our go-to, ‘working’ rifles are ready to go. A good maintenance schedule allows one to prevent problems that may crop up at the most inopportune times.

Much like your car has a maintenance schedule, so should your main fighting arm. Often, when the word, ‘maintenance’ is uttered, it conjures images of simple cleaning. While cleaning is indeed a part of maintenance (and nowhere near as important as has been suggested—more on than later) it is certainly not the only or the most important aspect of maintenance.

This subject is highly subjective based on a myriad of factors that include:
-Quality of platform and included parts
-Length of barrel
-Length of gas system
-Frequency/Intensity of use

Also, just like with your automobile, it is advisable to keep a logbook of maintenance. However, unlike with your vehicle, instead of oil changes and tire rotations etc, this logbook contains the number of rounds put through your platform and how they were put through (slow fire, moderate, full auto, suppressed etc etc). This serves two purposes: Allows one to inspect and replace parts prior to breakage and, in the event a part fails or breaks, allows one to note the round count and conditions when the breakage occurred.

Militaries around the world (both Western and Eastern) usually go by a, ‘run it until it breaks’ mentality. Some special units may have more vigorous inspection procedures but it is not the norm. That said, unlike members of the military, an individual owner is not likely to have a support staff to identify and solve problems (or to lend fire support in the event it’s needed).

Basic Maintenance

Basic maintenance refers to three facets: Cleaning, inspection, and lubrication.

Cleaning
The AR-15 does not have to be cleaned every five shots, as many people on the internet will tell you. Part of the reason why this myth is propagated are the white-glove inspections done in the military. If anything, cleaning at a rate of one-time per week or extensively after every short range session can be most unbeneficial to the life of the platform. Cleaning is actually rather unimportant as far as keeping it chug-a-lugging (lubrication is the main issue but more on that in a minute).

However, a good cleaning allows for an easier inspection of wearing parts. While one can keep an AR-15 running for thousands and thousands of rounds through simple lubrication, it is not advisable because not all parts can be properly examined through a thick coat of carbon fouling.

Even if the rifle is kept well lubricated, it should be cleaned thoroughly at least every one-thousand rounds. Cleaning prior to five hundred rounds, unless the arm is going to be stowed for a long period of time or corrosive ammunition is used (a virtual non-issue with 5.56 rifles), then cleaning is not usually beneficial. It took me a long time to break the habit of an extensive cleaning after every use (I used to refer to it as, ‘communion’) but being intellectually honest about over-cleaning helped break that long held bad habit.

Cleaning involves deterging the chamber and bore, stripping the BCG and cleansing its parts completely, and a simple wipe-down of the trigger mechanism. The action spring and buffer only require a cursory wipe-down. The persistent carbon fouling on the tail of the bolt is not an impediment to function although cleaning it does not negatively affect function in any way. The rim of the extractor should be free of debris. The gas tube of the weapon does not have to be cleaned out with extra-long pipe cleaners (ever!) and the rifle does not have to be disassembled far beyond it’s normal break-down.

Inspection
After cleaning, an inspection of parts should take place prior to lubrication.

Measure the Action Spring. A rifle length Action Spring should measure between 11 3/4 and 13 1/2 inches and a Carbine length action spring should measure between 10 1/16 and 11 1/4 inches. If the action spring is shorter, replace it immediately. Examine the bolt face and locking lugs for any unusual wear, or cracks. As the round count increases, or with a "lower tier" (non magnetic particle inspected bolt, constructed from a lesser grade steel than milspec), this bolt inspection becomes more critical. Bolt locking lugs typically shear in use, but inspection for visible cracks may catch it early. The disconnector should be closely looked at (complete disassembly of the FCG (Fire Control Group) is not necessary for this) for any unusual galling or wear.

Closely inspect the Bolt Carrier Key for any signs of damage, impact, and to ensure it's still round. Inspect the gas tube where it extends into the upper receiver for deformity and straightness. (It can commonly become bent during extreme malfunction or by dropping the bolt carrier assembly onto a hard surface) Upon inserting the BCG back into the upper receiver, make sure there's absolutely no interference between the carrier key and gas tube and that it slides smoothly into place.

Although, ‘stoning’ of triggers is advocated by many in the shooting community to allow for a smoother trigger pull, I recommend against this. The FCG parts, assuming mil-spec, are hard phosphated to reduce wear. Willingly taking off this coating (with a dremel tool or otherwise) allows for the FCG parts to wear out much faster than they would normally because they are only surface-hardened and it’s very easy to stone through it. If one is in a DMR role, select a trigger which is suitable from the outset instead of trying to, ‘tune’ a mil-spec trigger into something it was never intended to be.

Other inspections/tests take place after lubrication and will be covered shortly.

Lubrication

Take a close look at the BCG. Wearing parts show their hand in the reduction via friction of the phosphate coating they contain. The general rule is, “if it’s white, lubricate it”

Apply grease/lubricant to the red areas shown and also a tad on the underside of the BCG where the hammer drags (yes, I turn staking of the gas key into absolute bloody murder, haha).
http://img.photobucket.com/albums/v11/DavePAL84/projects/maint1.jpg

Apply lubricant to the areas of wear evidenced on the bolt (as shown). A drop or two of lubricant on the gas rings is beneficial.
http://img.photobucket.com/albums/v11/DavePAL84/projects/maint2.jpg

The firing pin channel should never be lubricated.

I like to apply grease to the areas of obvious wear (as shown above) and a thin coat of lubricant over everything. Placing a couple of drops into the two holes on the right side of the BCG will effectively lubricate the gas rings of the bolt (something easy to do during training without further disassembly).

http://img.photobucket.com/albums/v11/DavePAL84/projects/maint3.jpg

A bit of lubricant/grease on the top of the charging handle where it wears on the upper receiver is also a good idea as is a bit on the top of the hammer.

For a long time, the military advocated (and unfortunately in some units still does (institutional inertia is strong)) using less lubricant in the desert. The idea was that more lubricant attracts sand and/or other environmental fouling. This is one of those ideas that holds its roots in theory than actual practice. A wet, dirty weapon will always run better and longer than a dry, dirty weapon.

There is a lot of debate out there about lubricant. For general use, I prefer TW-25B for grease and Militec-1 for oil to lubricate the AR-15. However, most of the lubricants out there will do the job (though I do no recommend using anal ease on a rifle, ask me how I know!) Not all lubricants are equals and I advocate doing research on what’s right for you. One could probably write for days on aspects of different lubes for rifles.

So long as the system is kept lubricated, it will run for a long, long time. That said, some uses will eat lubricant far faster than others. Suppressors eat lubricant (especially when used with a full auto or SBR) far faster than with normal use. As such, lubricant needs to be applied more often with rifles that utilize sound suppressors. Proper application of lubricant for a non-suppressed, non-full auto rifle should be done every 300 to 500 rounds to ensure reliability.

Unless one is running a new gee-whiz coating on their BCG (such as FailZero, which has held up to testing quite well with no lubrication at all), lubrication should be made at the prescribed intervals to avoid weapons failures.

After lubrication, one should check the gas rings located on the bolt. No, the lining up of the gas rings does not cause the rifle to malfunction nor does it cause a singularity to open up in your living room. There are a couple methods to inspect if the gas rings are within specifications but this is the method I like:

-Lubricate and assemble the BCG
-Pull the bolt forward as far as it can go
-Place the BCG face down onto the bolt face on a hard surface, standing it upright

If the bolt retracts into the BCG under its own weight, then the gas rings should be replaced. Other valid methods exist but this is the most presumptuous and malfunction-reducing method that I know of. Some items exist, such as McFarland one piece gas rings, which will improve the longevity of the gas rings, and I fully support their use.

Functions Check
After every assembly, a functions check should be done on every rifle (this is technically a part of inspection). A functions check exists to ensure that the selector lever and rifle are properly functioning.

*This check should only be done on an unloaded rifle!!* I know it sounds silly to stress this point but, after all, no one is ever accidentally shot with a loaded rifle!

-Assemble the rifle completely
-Pull the charging handle to the rear and release
-Place the selector lever on, ‘SAFE’
-Pull the trigger, the hammer should not release
-Place the selector lever on, ‘SEMI’
-Pull the trigger to the rear. The hammer should release.
-Keep your finger held back on the trigger, pull the charging handle to the rear and release. The hammer should not fall. You should feel the sear reset.
-Place the selector lever on, ‘SAFE’

This completes the functions check for semi-auto AR-15’s. There are more steps for automatic/burst rifles which are here:

AUTO
-Perform functions check as listed above
-Place the selector lever on, ‘AUTO’
-Pull the trigger to the rear. The hammer should release
-Pull the charging handle to the rear and release. The hammer should not fall
-Release the trigger and pull again, the hammer should not fall

BURST
-Perform functions check as listed above
-Place the selector lever on, ‘BURST’
-Pull the trigger to the rear. The hammer should release
-Pull the charging handle to the rear three full times then release.
-Release the trigger and pull it rearward again. The hammer should fall.

If your rifle does not pass the functions check, ensure the FCG is properly assembled. If it indeed is, seek the counsel of a certified armorer.

Parts Replacement

Wearing parts on a fighting arm should be replaced before the end of their service life. However, the actual service life of each part depends largely on manufacture and the manner which it is used. The longer the gas system is, generally the longer the parts will last. Shorter gas systems and shorter barrels expose parts to far faster wear than longer gas systems and longer barrels. This breakdown is generous as to be the most universal.

As with anything manmade, sometimes parts will not fulfill their intended lifespan but fail very quickly. I once had an action spring from a reputable manufacturer fail at under 800 rounds (this part should have lasted far far longer) but due to circumstance, happened to fail much sooner. (As a side note, Gas Port diameters can and do vary greatly between barrel manufacturers. Many "hobby grade" manufacturer's carbines are severely over-gassed, and matching the correct (heavier) recoil buffer weight for the individual carbines gas port size will greatly extend the life of the action spring.) Just like when one replaces the serpentine belt on their vehicle, old parts should be retained as replacements then substituted if need be (properly marked, of course. I like to use zip-lock bags with the round count marked on the outside).

Being that this guide isn’t for armorers or people with an extensive armory support (or even men to lend fire-support), it is very conservative as far as replacement. That said, the cost of replacement parts is so minimal relative to ammunition count (even with Wolf ammo!) it makes no sense to follow the old, ‘run it till it breaks’ mentality. Easily, parts replacement is literally 5% of ammunition cost at this level.

Every 10 thousand rounds, replace*:
[ ] Disconnector
[ ] Extractor
[ ] Extractor spring and insert
[ ] FCG springs
[ ] Firing Pin

Every 15 thousand rounds, replace:
[ ] Bolt
[ ] Action Spring

Every 20 thousand rounds** replace:
[ ] Barrel
[ ] Gas tube

As you can see, 10,000 rounds is the, ‘magic’ number for replacing most of the parts. If one has the economic capability and mechanical ability, I recommend replacing most all parts at that number. Obviously, if the rifle is run FA and suppressed 24/7, parts breakage will be much sooner. If that’s the case, cut everything in half and move forward. Having quality parts from the get go (like HPT bolts and chrome barrels etc) will improve the longevity of your platform.

Nothing runs forever, especially when run hard. Use this as a general guideline for your maintenance schedule and divine accordingly for the rest. I wish I could give everyone a list for their carbines but given all of the variables that take place it would literally be impossible.

Spare parts

It’s always advisable to have some spare parts available. Instead of carrying a spare extractor and spring (which are easily lost in the field), carry a complete bolt assembly (which is both easier to replace and harder to lose). A spare firing pin never hurt anyone either.


*This is designed as a guideline for working (SHTF) rifles. We always recommend having a training rifle setup as closely as possible to your main fighting arm. If you have a training rifle, we recommend running the mentality of, ‘fix it when it breaks’ (but still make note in your logbooks) since the purpose is solely training. IE: Don’t replace the barrel on your training gun unless accuracy diminishes and don’t replace your extractor until it fails.

**Wolf ammunition is currently selling for around $200/ thousand. It's very, very important to put things in perspective. By the time you've reached the 10,000 round mark, $2,000 has been spent on ammunition. In comparison, $50 in small parts as PM is financially insignificant.

THCDDM4
08-31-10, 14:31
Thanks for the post, that is very imformative.

NMBigfoot02
08-31-10, 14:44
Sticky material.

mike_556
08-31-10, 15:23
Doesn't the FM say to drop a drop of CLP into the firing pin protusion hole? Unless that's NOT the channel you're referring to...Otherwise GREAT post :)

jaxman7
08-31-10, 15:34
As always Dave your posts are very informative and thanks!

-Jax

TOrrock
08-31-10, 15:42
Thanks for putting this together.

Now a sticky.

Irish
08-31-10, 16:06
This is a great thread that should be bookmarked by many. Thanks for your efforts!

carshooter
08-31-10, 16:29
Since this is such a common question, your inspiration to begin writing this was an excellent idea. Now there's a very basic reference to steer to.

I'm glad that I was able to contribute.

Heavy Metal
08-31-10, 18:31
If you are going to replace the Disconnector, you should proabally replace the Disconnector Spring and the Hammer and Trigger Springs at the same time.

I would also recommend replacing the Gas Rings at 10K too.

Mark71
09-01-10, 07:56
Excellent info. Thanks for taking the time to post this.

dail621
09-05-10, 10:12
Anal ease... hahahaahaha

Killjoy
09-05-10, 21:23
Excellent article!

St. Dark
09-17-10, 12:36
Now, see, it's stuff like this I would be less likely to run across "in the wild."

Years ago, when my shooting friends drug me off to the gunstore to get the mini-14 they insisted was "totally me", they instilled in me "if you shoot it, might as well shoot it a lot since if you shoot it, you gotta clean it."* My wife will tell you that while I don't always have that attitude with other things :rolleyes: , I did with the mini and do now with my SporterII in the year and a half or so that I've had it.
Nice to be able to get SOLID info from qualified sources.

*in their defense, none of them owned AR's; and the anal retentive school of gun maintenance was probably a GOOD thing with the mini.

barrelwrench
09-23-10, 21:07
Good quick refresher guide. I haven't re certified in the last few years.
Question on gas ports? Do you have some info on specific manufacturer, carbine length and rifle length gas port diameters.
Another question? I heard that Colt has redesigned or improved the locking lugs last year. Any truth to that?

m4fun
09-23-10, 23:42
Very well put together. A sticky vote as well.

JDW67
10-20-10, 12:50
"Troglodyte" :laugh:

BVickery
11-03-10, 23:02
Great help!

Does anyone know of a good video to teach one how to break down a BCG?

MikeCharlieUniform
11-04-10, 10:47
Great help!

Does anyone know of a good video to teach one how to break down a BCG?
http://www.youtube.com/watch?v=t0J_zvWEnzw

7 RING
11-27-10, 11:19
Maintenance ? Who performs maintenance ?

HawaiianM4
12-04-10, 23:56
Excellent post. Wish someone could post of video about this.

ColdDeadHand
12-05-10, 14:25
DavePAL84,

As someone who is VERY new to the AR platform, thank you for this post. I printed it and will re-read it in "the office". Also started a small log book.

JeffWard
03-10-11, 15:22
Great post... Makes me smile. I've been doing all of this EXCEPT for the drops of oil into the BCG holes for the rings. I'll add that step. Never saw that ring test (Extended bolt on face).

Thanks!
Jeff

sgtjosh
05-13-11, 19:37
Thanks for the no BS lesson. I like that you dispelled many commonly held myths.

MichaelZWilliamson
05-18-11, 20:03
For a long time, the military advocated (and unfortunately in some units still does (institutional inertia is strong)) using less lubricant in the desert. The idea was that more lubricant attracts sand and/or other environmental fouling. This is one of those ideas that holds its roots in theory than actual practice. A wet, dirty weapon will always run better and longer than a dry, dirty weapon.

This is completely against my experience--wet weapons get muddy and jam quickly.

There seem to be two functional extremes and no happy medium. Either:

Run dry or with dry lube--the DI gas system blows sand out (and into your teeth, but you can spit), and save oil for repair if you have problems (I didn't).

OR, lube the everloving hell out of it until it drips. It will run well, spit oil, and flush sand out in the process. It'll be dripping on you.

In between is lubed, and muddy.

Also remember that a dry weapon MAY get dusty. A wet weapon WILL get muddy.

This also depends on which desert you're in, the humidity level (God help you, humid not only feels bad, the sand forms concrete), and the number and quality of sandstorms you're in.

Funny as hell aside: I have video from last week at KCR of five guys with ARs blazing away, while an AK goes BANG click BANG click click BANG click.

Littlelebowski
05-19-11, 11:13
There's any number of folk on here who would rather have a wet, dirty weapon than a dry, dirty weapon, Michael.

I suppose if you want to split hairs, actual mud is worse than dirt. But carbon and grit mixed with a lubricant is not the same as actual mud in my book.

markm
05-19-11, 11:17
Looks good. However any lube on the bolt tail is blown out on the first shot so... other than corrosion protection between shoots, the lube isn't there during operation.

MichaelZWilliamson
05-19-11, 11:31
Middle Eastern "Sand" is fine clay. It gets into everything, and I've seen stuff with 10 year service life burn out in 18 months.

A certain amount of dust gets into everything. When it does, cleaning is necessary. (This includes through covers with torqued on plates and rubber gaskets. It gets into EVERYTHING.)

Dry or no lube means just dust. Light lube means lube mixed with dust = mud. Heavy lube means mud drips out with the lube.

If you read what I said, I didn't contradict heavy lube. It works, though it's messy.

Dust gets blown out. Mud does not. Mud can be washed out with enough lube.

In my experience, it's an all or nothing proposition. If you're lubing in the desert, lube heavy.

Dave_M
05-19-11, 22:37
Your personal experience is trumped by the experiences of tens of thousands of competent American Soldiers & Marines who have been fighting in the desert for only, say, the last decade or so...

900ss
11-09-11, 22:00
Great post OP, thanks for taking the time.

5102Yuma
11-20-11, 18:22
Straight out of basic training 101. Good job!

munch520
11-30-11, 15:32
Great post OP, thanks for taking the time.

Here here. Never hurts to get back to basics. I find myself reading this thread often.

Bushido1971
05-06-12, 13:54
I recognize this is an old thread and I am a newbie here on the boards but reading through the posts I figured I'd chime in.

I'm curious as to how we dispelled this notion that the position of the gas rings is irrelevant? In their armorers school, Colt is advocating that the rings be alternated.

As an instructor, SWAT operator and armorer, I would tell people that it's better to do as the manufacturer recommends and avoid any potential problems. Yes, the gun will likely function fine dirty, fouled and with rings lined up. But this is one of those things we have control over, so why not control it and avoid a potential "oh shit" moment?

BTW, the original post was awesome. I certainly do not mean to contradict any of the great information that was posted. Just sayin'.

Littlelebowski
05-06-12, 16:09
Pat Rogers tested it with one gas ring and it ran fine, bushido.

I think the gas ring rule from Colt is like the silly "only shoot factory ammo, not reloads" disclaimer most manufacturers use.

I wouldn't run around advertising myself as an "operator" on the internet coupled with listing my AO, FYI. There's quite a few real world military operators on here that practice PERSEC religiously.

Dave_M
05-06-12, 22:31
Here's the long and short of it:

No one has even shown that the lining up of gas rings has ever caused a failure. Ever.

It's one of those, 'theory meets practice' things. In theory it could be a problem but in real use it has never reared it's head. Ever.

I'll bring it into perspective, Colt armorers class could advocate that one should always say, 'Abracadabra' every time a rifle is assembled or it might malfunction.

This is to say, if saying, 'Abracadabra' (or not lining up gas rings) makes you feel better then by all means do it; you aren't hurting anything. However, I won't be enchanting phrases nor offsetting gas rings anytime in the near future...

tpelle
05-07-12, 18:26
The gaps in the gas rings are just like the piston rings in your car engine - I mean that they are EXACTLY LIKE the piston rings - in that when you insert the bolt in the carrier the rings are squeezed so that the gaps close up.

soulezoo
11-07-12, 16:25
Now for required listening, look up troglodyte as performed by the Jimmy Castor Bunch circa 1973.
I promise it is worth the effort!

GSPKurt
11-29-12, 20:02
Thank you for the thread.