The AR is a mainstay in the tactical realm – what’s more, they are America’s Gun and have a worldwide adoption where allowed. The proliferation of AR components, parts, kits, firearms, and ammunition are incredible. Yet, it exists because demand stays ever present. Whether you want to upgrade your lower receiver or any of the internal components, you will never run out of options.

After a few dicey years of the newcomers to the industry practicing market cycles on their training wheels, the industry now knows exactly how much product to put out there. And it’s a huge amount of product.

With millions of rifles and pistols based on the AR, the consumer and real world user of the AR system should be well aware of the maintenance and armory needs of the platform – and when to replace parts or perform maintenance. 

That’s the goal of this article: to speak to the importance of having parts on hand; lay out a relative spectrum of maintenance and parts checking and provide a good checklist regarding how and when to feed your machine, so it stays in optimum working order. 

Which AR Parts Are Absolute Must-Haves in The Armory, Or in Your Workbench Drawer?

• Spring Kits – as in more than one – or at least more than one of the essential springs
• A Rise Armament trigger group can be useful
• A full pin replacement set (including detent cups, etc.)
• An extra gas tube for your selected system length
• A carrier key and screws
• Extractor and ejector (the ejector usually comes as part of the pin kit or full parts kit)
• A buffer tube and spring
• Sprinco magazine spring kits to ensure your mags won’t fail
• Basic maintenance tooling like a Geissele barrel wrench and sight adjustment tools and carbon scraper, etc. 
• A hammer and punch set, including a roll pin punch set for those that don’t like seeing deformation on roll pins
• A good set of rags and a solvent you trust along with a thin gun oil and a thicker gun grease; preferably a molybdenum disulfide or copper disulfide, or something that can be monitored more easily and trends “dry”
• Some blue Loctite or similar thread locking compound – red if you’re daring (but don’t blame us if you cannot get parts apart again with the red)

How Regularly Should You Check for Wear and Tear?

Below we will detail a specific regiment and tweak it slightly for different types of volume shooters. You should always be on the lookout for things that don’t feel “right”, though. Be aware of your firearm and stop if you feel like something wasn’t normal.

Don’t be afraid to check why a round did not seat properly, or a load felt too weak or too strong; or you were several inches off target. 

 

How Much Lubrication and What Types Make the Most Sense for an AR

Guns in general need less lube than one might think. Most firearms only have a few places that require lubrication because of several reasons:

• Unless a surface treatment is non-existent (meaning bare metal, oil or other lubrication is generally reserved for the areas where actual friction or consistent metal on metal contact occurs
• Oil and other lubricants can actually increase the opportunity for debris collection and increase potential malfunctions in certain places on a firearm
• Heat is an important factor to keep an eye on, but with regards to firearms, lubrication isn’t generally centered on places of high heat, like it might be in a different type of industrial application (e.g., in a motor, or as a coolant in a passive cooling system on an electrical system)
• Oil can be messy and annoying during the firing of a firearm
• Very few parts interact with each other in firearms on a metal to metal surface level, and if they do the spot of contact is tiny relative to the firearm, generally
• Many firearms utilize different composites, hybrid systems or simply different materials in conjunction and with physical connections to other parts
• Barrels, bolts, and trigger systems have specific hardness ranges that play well with each other to minimize wear potential. In the case of an AR, a hardened steel bolt rides in a hardened steel carrier, with a hardened steel cam forming a physical connection between them. They are hardened to within a few RC (Rockwell C-Scale hardness level of each other). The harder a steel part is, generally the less easy it is to mark up or degrade the surface through friction (even if extreme hardness can sometimes cause steel to become brittle upon impact). These parts are riding in anodized aluminum upper receivers and mate with a hardened chamber and a hardened and chrome plated gas system, generally. The net requirement for lubrication on a liberal basis is about 8-12 drops of oil for most guns at any given time.

Aluminum And Steel Don’t Make Good Partners When You Introduce Certain Chemicals

Speaking of hardened steel riding in hard anodized aluminum – aluminum and steel don’t play well together under certain circumstances. Here are a couple of reasons why they don’t:

• Even though the Aluminum is “hard anodized” it doesn’t mean that it’s anywhere near as hard as a piece of hardened steel on the upper end of the RC scale (most bolts and carriers are more than 62RC and some around 70-85RC – especially surface treated specialty object). The treatment is only a few millimeters thick. The upper receiver for example might be measured on an objectively different hardness scale, like the Brinell, Vickers or Rockwell B scale.
• Hard anodizing is almost more art than it is science. Yes, of course certain levels of chemicals are needed, and yes, there is a best practice for how to perform the task, but no two batches are really the same
• When aluminum (bare) and steel (bare) come in contact and sit in close proximity for extended periods of time – leeching and corrosion can occur. Finally the connection can cause real world issues in the form of heavy corrosion
• Furthermore many lubricants and solvents can cause corrosion in dissimilar metals when they sit together in that solvent or lubricant. 

Here’s what you need to know about to keep them operating safely and smoothly without premature wear: 

• A thin layer of grease is often better than no lube for wearing surfaces like the interior round-shaped channel of the upper receiver; it’s usually much better than oil, which can have more powerful solvents included in their chemical composition
• Using molybdenum disulfide or a similar “dry grease” type (thing choke tube lube) can have a drastic impact on longevity – ensure they grease you use will not embed into the aluminum and is safe for use on dissimilar metals
• Thin is your friend – don’t use streams of oil, wipe oil to fully coat the area and check for specific areas of wear which can be manifested by the consistent degradation of the surface area in a place where two dissimilar metals have been in repeated contact

What Needs to Be Cleaned Every Single Time You Shoot?

An important note: never fire a cartridge that the barrel is not marked to accept, or for which you are uncertain of the pressure standards relative to the barrel. E.g., do not fire a 5.56x45mm in a .223 marked barrel, unless it is also marked as capable of firing 5.56x45mm.

There are many schools of thought on this one. And really it depends on how much you shoot and how bad the ammunition fouls the key areas (bolt face/gas system/extractor/chamber/bore).

If you are not seeing much fouling and don’t see anything wrong during your safety checks after shooting and before your next outing, you can probably get by without a cleaning or with a basic wipe-down of these areas. No matter what, every 500 rounds you should be at least field-stripping and cleaning key areas to ensure that you can operate safely.

Depending on how tough you are on your guns and the environment (think flying sand, etc.) and the type of ammunition/cleanliness of the ammunition – this could be every 100 rounds, or every 250 rounds fired. 

Generally, most commercial factory fresh loads will afford you decent cleanliness and your gun won’t be having difficulties for 500 rounds, where it needs to be cleaned before you finish that range session. 

There is no reason you cannot make a check every magazine load or a significant check if there is a misfire, misfeed or malfunction. 

Every 100 rounds you should be checking for basic cleanliness to keep your gun running smoothly. There are times/conditions where you can get away with firing 1000 rounds without a thorough cleaning, but it’s highly recommended you don’t do that. 

Any time you see or feel the following, you should stop what you are doing and check the gun thoroughly for safety concerns:

• A round that didn’t feel right; recoiled incorrectly (too hard OR too soft); or any round that seemed too loud compared to others, or too quiet
• Any malfunction that cannot immediately and definitively be attributed to a bad primer or a case with a nick in it, etc. 
• Multiple extraction failures in a single magazine
• Striated or cut cases that seem inappropriately abused
• Any case head separation
• Any malfunction not easily resolved by a forward assist or by re-racking the charging handle

You should clear the firearm and ensure it is unloaded before attempting any other safety check.

Properly Breaking in A Barrel

A barrel used in a basic AR won’t generally have a need for a specific break-in strategy, but it can be a best practice to observe the common principles of breaking in a barrel to ensure that no fouling is going to cause issues. Every competition shooter is going to have a regimen for breaking in a tight barrel to ensure proper accuracy. It’s hard to state one here that most will agree with.

Go easy on the lapping compound if you are breaking in a barrel for precision shooting and start with the highest grit (least aggressive compound).

To break in a barrel, take a shot then clean the barrel with a patch and oil. Avoid solvent during the initial break in phase unless you are prepared to fully clean the barrel to neutralize any etching potential from the solvent. 

After the next two shots do the same. Then take 3, clean with a patch and light oil. Each set of shots you will want to check the bore for fouling, flaking, debris and odd striations in the barrel caused by fouling.

This author prefers to use all copper rounds for the initial break in period because the monolithic build and the harder metallic compound tends to perform the necessary “smoothing” more easily with easier to see “fouling”.

You can repeat a couple more times until you have shot enough to feel comfortable with the basic rifling profile. Clean the bore and chamber thoroughly and then transition into the rounds you would normally plan on shooting. 

This is an incredibly basic barrel break in procedure – and if you are super concerned with your barrel, you should do your own research and get multiple viewpoints. Generally, the manufacturing attention to detail and the modular, general-precision nature of the majority of the AR’s on the market, barrel break-in is not a super-hyped component of preventative maintenance outside of ultra long range precision or competition shooting.

Only you will know if your AR may be steering towards more precision tasks and whether you need to explore the concept further.

What Are the Biggest Culprits for Compromised Reliability?

In no particular order:

• Poor quality ammunition
• Gas tube bending
• Weak mag springs
• Poor maintenance on the bolt/breech/chamber
• Modified buffer springs or cyclic rates by tension or weight
• Poor handling of the firearm 
• Too much lube

The Basic Maintenance Cycles for Shooters of the AR

Every 250 rounds – Perform a visual check; and a wipe down of key components *(bolt face and lugs; extractor area; chamber and feed area; bore; exposed gas system areas)

Every 500 rounds – another visual check and wipe down of key components since it’s a stop along the “every 250 rounds” arc; look at the magazines for excessive debris on followers or inside the first couple of inches of the magazine; basic visual check of the muzzle for accumulated debris; and the buffer tube area as well to ensure the debris is not excessive.

Generally, a close inspection of the hammer/trigger/sear from a visual level is helpful (a flashlight is a good tool here), and pay close attention to the carbon, debris and fouling on the bolt face, carrier gas area and the chamber.

Possibly running some solvent and cleaning the bore and chamber in addition to the wipe down of the key components will make sense. You will want to properly lubricate the appropriate areas of the firearm at this point as well. Note that additional lubrication will speed up the need for cleaning; especially if there is already accumulated debris and unburnt powder, etc. 

Additionally at 500 rounds, you will have a good idea of how the rifle and the ammunition, and the magazines are prone to foul and how they behave relative to each other. 

Every 1000 rounds – a full clean with at least field stripping and close attention paid to the gas system components. 

Every 2500 rounds – checking for more excessive wear and tear in metal parts. Checking for excessive lead or copper fouling in any of the chamber or bore areas, including the muzzle brake area. If you are using a suppressor, you should be doing this at least every 1000 rounds, and more like every 500 rounds.

The additional debris accumulation can be a serious concern if you are not monitoring it. It can cause excessive pressure and lead to a special class of issues. Check how tight the handguard and internal fitment of parts is progressing.

Ensure that all component parts are still tightly locked down with mechanical fasteners. Check for excessive play in the pins and for weak springs. 

Every 5000 rounds – check barrel for excessive wear and check headspacing and basic measurements for your chosen ammunition/load. A full disassembly should be performed to ensure gas components are functioning properly and to check for excessive wear of components and for spring wear. Check for excessive pin looseness.

Check for any striations or detrimental effects inside of the chamber. Check the cam to bolt to carrier fitment and the front and rear of the firing pin. Check for deformation on the firing pin hole and any wear that looks uneven on the bolt face; lugs and chamber.

Check for any type of “peening” or “stretching” on any of the key components. Thoroughly clean with brushes and solvents to ensure that all excessive fouling is removed. Disassemble beyond the normal field stripping if possible. 

This is a good interval (5k rounds) to check for hairline cracks across all parts of the firearm to see if you can determine any impact deterioration or hard use concerns in the whole of the firearm.

Every 10,000 rounds, expect to do a spring update on buffers and magazines, depending on how many magazines you run. If you only run a couple, this is a good time to change them, as 5k+ rounds will be enough to possibly impact feeding reliability.

Your mileage may vary depending on mag type, manufacturer, and general usage statistics. Check trigger/hammer/sear surfaces for wear and degradation. **If at any time you have a multi-shot release (2-3-4 shot burst that is unintentional), you should immediately check these surfaces and the springs associated with the trigger group. 

Barrels for most normal velocity rounds (less than 3500 fps velocity on average) should last a range of 12-20K rounds or so.

If they are chrome lined you might squeeze a bit more life out of them, but that’s not as normal an option as it once was because the accuracy concerns and the fact that chrome lining didn’t mitigate normal wear most often for most shooters anyway. Additionally, there is less of a proliferation of “mil-spec” barrels like there once was. 

If you are shooting a very high velocity round or have a specialty upper that sees heavy velocity up-ticks for your chosen cartridge, or you are trying for the ultimate in accuracy you should begin monitoring the barrel for noticeable degradation in accuracy around 5-9k rounds and keep monitoring after that. Most barrels will be good past 12k rounds easily. 

If you are shooting multiple types of ammunition; particularly dirty ammunition; reloads that utilize lower quality powders or are in an environment that is particularly windy or dirty, you should increase the amount of checks/lower the time between intervals.

If at any time, you see a bulge or ring in the barrel, or any bore or chamber anomaly or deterioration, your firearm is not generally safe to fire. It should be checked by a qualified gunsmith, armorer, or replaced. 

Light Shooters

You’re most likely a light volume shooter if the following is a good representation of you and your habits when shooting an AR:

• Shoot less than once a month
• Shoot less than 100 rounds at each range outing
• Buying moderate or top quality ammunition with brass casings and decent powder and boxer primers

Here’s a good schedule for light volume shooters for maintenance:

You should clean the following areas of your gun at the paired interval: 

See the above content for the 250 round cleaning regimen. 

Generally, a light clean and wipe down and a basic bore cleaning with light oil or light solvent and then dried with patches and oiled lightly, will suffice if the interval and volume is so low. There are AR’s in existence that have never been deep-cleaned because the volume is so low.

You’d be surprised with the right ammunition and a basic wipe down, how much maintenance you can avoid if you shoot infrequently. 

You should expect to have the following parts and be checking for obvious signs of breakage, loss in fitment, spring tension and general wear at the paired interval and the listed locations on your firearm:

See the above content for the 2500 and 5000 round count for basic standards over time. You can check these more frequently than this interval, and it may save a lot of headaches to do so. 

Moderate Shooters

You’re most likely a moderate volume shooter if the following is a good representation of you and your habits when shooting an AR:

• Shoot once a month up to 2 times a month
• Shoot less than 500 rounds at each range outing
• Buying bulk ammunition in case loads not by the box.

Here’s a good schedule for moderate volume shooters for maintenance:

You should clean the following areas of your gun at the paired interval: 

See the above content for the 250 round and 500 round count cleaning regimen. 

You should expect to have the following parts and be checking for obvious signs of breakage, loss in fitment, spring tension and general wear at the paired interval and the listed locations on your firearm:

See the above content for the 2500 and 5000 round count for basic standards over time. You can check these more frequently than this interval, and it may save a lot of headaches to do so. 

High Volume Shooters

You’re most likely a high volume shooter if the following is a good representation of you and your habits when shooting an AR:

• Shoot more than twice a month
• Shoot more than 500 rounds at each range outing
• Ammunition doesn’t matter as long as it goes bang – “If it seats it yeets”
• You have dark, powder and lead covered hands after every range session, and you smell like smokeless powder at least 3 days a month

Here’s a good schedule for high volume shooters for maintenance:

You should clean the following areas of your gun at the paired interval:

Check your AR every 500 rounds. Period. If it’s running fine, then look for obvious debris or safety concerns. If it’s getting sluggish, clean it and lube it – properly.

You should expect to have the following parts and be checking for obvious signs of breakage, loss in fitment, spring tension and general wear at the paired interval and the listed locations on your firearm:

The above regimen for 250 – 10,000 rounds is a good roadmap for high volume shooters. You may not need to check so often; there are a lot of factors that can positively affect how often you have to clean. Note, however, that there is not a substitute for a safety check. You should be checking for safety concerns at least every 250 rounds as listed above.  

Your high volume shooting may require more frequent checks for safety and maintenance, especially as the round counts go above 10k – 12.5k. This is a good time to check hard wearing components for replacement.

Even the best firing pins; springs and bolt faces will show significant usage wear at this point. That doesn’t mean it’s an unsafe endeavor to keep using them, but it does mean you should be aware that you need to keep an eye on wear and performance going forward on those parts. 

An Important Note About Heat and Rate of Fire

When you accumulate round counts at the higher end of the spectrum it means that you need to service and look for safety and maintenance problems more frequently. This is even more true when you are shooting 50 rounds at a time as fast as you can fire and going until your barrel is smoking from heat and oil is starting to creep out of the metal’s pores.

If you are frequently firing more than 100 rounds in less than a few minutes, you will need to monitor your gun for wear and damage and safety concerns more frequently. 

A total of 450 rounds fired in close succession can kill a barrel if you do it the wrong way. 750 can melt gas system parts. If the gun is getting too hot to hold you may have already gone too far. 

The best practice is to let the gun rest every 250 rounds if possible, with a basic visual safety and maintenance check. Letting the rifle cool down for fifteen minutes can ensure it has a long life. 

If you are shooting with a suppressor, these numbers should be adhered to strictly. The excess heat on the end of the barrel when you get into the rapid fire of more than 350 rounds can be damaging to component parts.

This is especially true of the suppressor, muzzle exit; chamber, bore and gas system, as well as the bolt face and carrier gas tube interface. 

In the end, you will need to maintain basic common sense when running your firearm to ensure it gets the longest life out of components and you remain safe. That’s stating the obvious of course, but a little care and maintenance can go a long way, and it’s better to be safe than sorry, generally.