AR-15 Maintenance Schedules and Guidelines

Thomas GomezStaff - July 8, 2020

An AR-15 rifle purchased from a reputable manufacturer is extremely reliable, though it does need periodic maintenance to function correctly. Basic maintenance schedules discussed below.

Some key points about the AR-15 rifle.

• The AR-15 firearm was designed to shoot 1 round every 2 seconds (Sustained rate of fire). If you shoot faster than that, you will drastically heat the rifle, and reduce the barrel’s life.
• Consider the Ar-15 a mini precision rifle. Yes, it can shoot fast, but the weapon, with the right optics, is best used with deliberate, aimed fire.
• Magazines can be a source of malfunctions. If you have a bad magazine, throw it in the garbage or mark it for “training purposes only.”
• A 5.56/.223 mil-spec/military-grade rifle can run at least 15,000 rounds before the barrel needs to be replaced. Some higher-end barrels can go 20,000 rounds + before they need to be replaced. An indicator that the barrel is worn out is the rounds key-holeing (hitting the target sideways) or an extreme loss in accuracy at 100 yards.
• The bolt carrier group is one of the most critical components of the rifle. On a hobby rifle, shoot your gun until a lug cracks on the bolt, then replace the bolt. If your life depends on your rifle, replace the bolt carrier group every 10,000 rounds.
• If you can afford it, carry a spare bolt carrier group with you. If your rifle fails during training, there is a good chance it is a component in the bolt carrier group. Simply swapping the bolt carrier group can get you back in action.
• If you cannot afford a training rifle or another bolt carrier group, at a minimum, carry a spare bolt with you. Before you train, swap out your “SHTF” bolt with a training bolt.
• Every time you clean your bolt carrier group, check for cracks. Cracks form around the cam pin and the lugs on the bolt. If you are missing a lug on your bolt, it is time to replace the bolt.
• While checking the bolt carrier group, check your gas rings, extractor, and ejector. A great way to check gas rings is to extend the bolt, then stand the bolt carrier group upright with the weight balanced on the bolt. If the bolt carrier collapses on the bolt, replace the gas rings. This method only works on a “Mil-Spec” bolt carrier group. You can check your extractor by removing it from your bolt and looking at the lip that holds the bullet case. If there is still a lip and the metal is not worn down, it’s probably okay. Check the ejector by taking a shell casing, seat it in your bolt, and let it go. If the shell is flung 5 to 6 feet away, the ejector/ejector spring are probably okay.
• Firing pins last a long time, but it is not a bad idea to keep a spare.
• Modern, well maintained AR-15’s do not need as much cleaning as people think. Wiping down the bolt carrier group with a carbon remover like M Pro7 is more than adequate. You can also use a bore snake and clean the carbon out of your barrel.
• After you clean your chamber and bolt carrier group, make sure to lubricate your bolt carrier group.
• Don’t fret about copper in your barrel, only carbon. Carbon pits barrels.
• Once a year, or every 2,500 rounds, give your rifle a very detailed cleaning (carbon removal) and check all surfaces for cracks.

On a training or hobby gun, you can keep track of firing schedules and diligently replace parts, or shoot the rifle until it stops working and then start replacing parts. If you carry a gun for a living, take firing schedules and parts replacement seriously.

Basic Maintenance Schedule for a 5.56/.223 duty rifle with a 14.7 or 16 inch barrel/Carbine or Mid length gas system. 

Please note, this is preventative maintenance. AR-15’s have been documented to run for 10,000 rounds + with no maintenance, save for lubrication. If you want to swap parts every 5,000 rounds, you will probably be okay.

• At 2,500 rounds, replace the extractor, extractor spring, and gas rings.
• At 5,000 rounds, replace the extractor, extractor spring, ejector, ejector spring, and gas rings. Check every surface for cracks, especially the bolt lugs and the cam pin area. You will need the bolt ejector tool, hammer, and punch to swap out the ejector and ejector spring.
• At 7,500 rounds, replace the extractor, extractor spring, and gas rings.
• At 10,000 rounds, replace the bolt carrier group, and buffer spring. Attach a precision rifle scope and shoot a few 3-round groups for accuracy.
• At 12,500 rounds, replace the extractor, extractor spring, and gas rings.
• At 15,000 rounds, replace the extractor, extractor spring, ejector, ejector spring, and gas rings and once again check accuracy. You will need the bolt ejector tool, hammer, and punch to swap out the ejector and ejector spring.
• At 17,500 rounds, replace the extractor, extractor spring, and gas rings.
• At 20,000 rounds, replace the bolt carrier group, buffer spring, and barrel. Have a certified armorer check out the system as a whole.

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Great post Thomas, lot’s of good info for those new to AR’s. Gonna piggyback off your post to say that if you just bought an AR and are freaking about having to keep it clean in a SHTF situation, don’t be. Look up the tale of “filthy 14” if you want some confidence as to how well the AR platform is capable of performing through long-term torture. If you’re really worried about it, stick a small bottle of oil in your pistol grip or stock. A little bit of oil can keep the rifle running a long time. Also a good brand for extra BCG’s that won’t break the bank is toolcraft, you can easily find them for under $100 and they’re g2g. If you want to really make it easy get a Nickel Boron BCG and laugh as the carbon magically slides off your bolt.

 

Thank you! I remember reading about the “Filthy 14”. That stole the thunder from the piston crowd. That bolt carrier group looks solid. Question, have you run Nickel Boron BCG’s for a while? I had one, and it kept eating gas rings. I was swapping my gas rings out every 1000 rounds. I think there was a rockwell hardness difference. Thoughts?

 

I happen to be one of those in that filthy piston crowd lol. I built myself a custom AR around one of the newer Adams Arms systems and I have to say it does stay remarkably cleaner. I mainly just built it so I can run junky steel suppressed and not have to clean as much lol. As for the NiB BCG, I have a toolcraft one in my other AR, has in the neighborhood of 1.5k on that bolt and haven’t had any problems so far. I know the NiB is supposed to be harder than a traditional Nitride or Phosphate coating but haven’t had any gas ring wear on it yet. It does make cleaning a breeze though. Just a wipe down with a rag and it’s good to go. The only issue I could maybe think of is perhaps your coating wasn’t perfectly bonded in certain areas? I’ve heard of people having issues before when the coat isn’t bonded correctly but that’s my best guess.

 

Pistons have a place, and it is neat to see that side of the industry evolve. That makes sense about the coating.

 

I fell in love with POF rifles back when I worked at a gun store that was an authorized POF dealer and so I’ve always wanted one. Since I didn’t quite want to shell out the cash for a POF, I built one for significantly cheaper out of Adams arms and POF parts specifically designed for piston use. Granted I spent years researching piston rifles before I built mine,  and I built it specifically to be a piston rifle. I don’t recommend people just trying to retro fit a conversion kit onto their AR, that’s how you cause issues. There’s advantages and disadvantages to it like with most anything else in firearms but I’ve always found them fascinating.

 

Frank DeSomma, the founder and president of POF passed away a few weeks ago. He was a really nice guy. Sad.

You are correct about taking a random AR-15 and trying to convert it. I think if I did a lot of suppressed work with a 5.56 at cold, high elevations, I would consider a piston.

 

How would you put this plan/kit into context of where it sits on the spectrum of “the essentials a noob needs” versus “what a pro would have? Very much appreciate it.

 

Hello! I made a bare bones kit, most of which can be carried on the rifle. If you have a spare bolt, you don’t necessarily need to carry the extractor spring kit and extra gas rings. At a minimum I carry this kit, because I am perpetually the armorer in my group and I carry enough gear to support at least another rifle. Let me know if you have any questions. Here to help indefinitely.

 

 

Hello Thomas – you recommend having a spare BCG on hand, and that makes sense to me. Based on what I’ve read online, a swap of the BCG means you should do a “head spacing check”. I’m experienced with firearms but NOT an armorer. Would appreciate hearing your thoughts.

 

Great question! 15 years ago I would have told you to check headspace everytime you bought an Ar-15, replaced your bolt or swapped out a barrel. The industry was chaos and unless you bought from a few very specific manufactures you had no idea what you were getting in regards to quality. Starting around 2012, a lot of great manufactures popped up and started producing military grade rifles that meet or exceed the original Colt Technical Data Package, which was the blue print on how to build a proper M4/Ar-15.

If you bought a rifle from a good manufacturer they would have checked headspace at the factory before the rifle shipped. If you bought a spare bolt from the same manufacturer, the chance of the system not being properly headspaced is very low. 

If you did a home build and bought all individual parts, in theory they should work together, but I would still check headspace.  The issue with headspace will lie with the chamber and bolt. 

The armorer in me says that you should check headspace everytime you buy a bolt, or swap a barrel, but from personal experience I have seen scores of home builds that were not checked and ran fine. When I say run fine, they survived a two day carbine course without issue. If your bolt closes and cycles fine, especially when the gun gets dirty, you are probably okay. If it will not close, or you need to agressively use the forward assist, check headspace. 

Some key points:

• Colt rifles can have an oversized chamber and will fail with a basic set of gauges. 
• If you are chasing extreme accuracy, you are going to want to check headspace (and get a nice aftermarket trigger).
• When it comes to checking headspace you will need to remove the extractor and ejector. You will need a hammer, punch and a fixture to hold the bolt. See kit below. 
• What happens if your rifle is not properly headspaced? Loss in accuracy, extraction issues, feeding issues, and worst case your round may detonate in the chamber.
• If you build and tinker with your Ar-15’s, or are the “village armorer” in your community, I would invest in the kit below. 

What do you do if the rifle is not headspaced correctly? If you bought it as a complete rifle, call your manufacturer. If it is a home build, the problem will be with the bolt, or barrel/chamber. At this point, contact a gunsmith or armorer. They will advise what to do. You may be replaceing a barrel, but they will tell you if the chamber can be opened up, or if you need a new barrel. 

Here is a kit on everything you need

Video on how to use the gauges

Video on how to take apart the bolt