AR Service Life?


December 12, 2012, 10:48 AM
Perhaps already covered....

I recently wanted an AR, and found a Colt LE6920. I like it except for the trigger which I will correct (different thread).

The rifle is fine and will be used only for plinking and such, and there is little chance I'll ever wear it out - I don't shoot too much rifle.

But it got me wondering: what is the expected average service life, in shots fired, for such a rifle?

For arguments sake:

Assume the rifle is kept reasonably clean, lubed, used hard but not abused.

Let 'service life' be defined as a 100% decrease in initial accuracy, e.g. from 2" to 4" @ 100 yds, or any measurable decrease in reliability from wear, or any part failure that makes the rifle inoperable.

Of course this will vary for each rifle, but there should be an expected mean and median for a commercial Colt, and other makes.

Any ideas?

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December 12, 2012, 11:12 AM
I would say minimum 10,000 rounds. Probably quite a bit more. It may need minor maintenance such as gas rings or maybe a new bolt after that, but should be fine. Someone with more experience will probably weigh in and give you better info.

December 12, 2012, 11:16 AM
A good point, thanks - I'd also be interested in how often such minor routine maintenance is needed, in addition to the 'reasonably clean and lubed'.

Jeff White
December 12, 2012, 11:21 AM
I have a Colt R6920 I bought on a letterhead in 1998. I would estimate it has upwards of 30K rounds through it. I have replaced the extractor, accuracy is still as good as it was when it was new although I will admit to not using it much at ranges greater then 200 meters.

Heat is one of the biggest wear factors. An M4A1 used by a special operations unit is going to to wear much faster then a 6920 owned by a private citizen and used for plinking and target practice or even carbine classes. The private owner just isn't going to heat the weapon up the way sustained automatic fire will.

December 12, 2012, 11:28 AM
10k is about right. That's about the point for most AR pattern rifles, you're going to start seeing parts wearing out/breaking. Barrel wear will be a different story as it most likely won't be shot out (unless of course a lot of long strings of rapid fire have taken place) you'll have throat erosion, and certainly a moderate amount of gas port erosion. Also I have seen several guns with 5-6k through them when the thin portion of the bolt(where the cam lug sits) cracked and had to be replaced, but that is somewhat rare.

December 12, 2012, 11:32 AM
On a quality rifle like the Colt, or others with chrome lined barrel, quality BCG's and properly made forged 7075-T6 uppers? If I were to hazard a guess, well North of 100k rounds with proper maintenance. Change the buffer & spring every so often (maybe every 10k rounds), keep the thing decently lubed to avoid galling of metal and you should never wear it out.

OTOH, I can't speak for more cheaply built guns. From what I've seen, a budget gun like Hess, Vulcan and even DPMS start to show wear sooner than guns from Colt, Armalite, S&W and other better makers. Different anodizing or other coatings on the inside of the receiver, BCG coatings and heat treatment-all this stuff makes a difference in the long run.

December 12, 2012, 11:35 AM
Are you talking about the service life of the barrel? The springs? Other internal parts? Or of the lower receiver itself? Hard to put a life-span number on a gun which can be constantly maintained and refreshed as parts wear.

FWIW, a lot of DCM match shooters will replace a barrel once a year or so -- maybe after just 5-6,000 rds? -- because the accuracy they want starts to decline. Of course, that is still far better than 2" at 100 yds...

December 12, 2012, 11:54 AM
I use an AR platform match rifle to shoot NRA High Power. I shoot heavy bullets: 75-80gr in a fast twist barrel. The only real maintenance I've had to do other than clean and lube, is replace the barrel after 5k rounds. With the barrel off the rifle, the throat wear and first 6" of rifling erosion is obvious. At 4K rounds it still shot almost 1 MoA; at 5K it was shooting 3 MoA.
I have replaced the firing pin due to a pierced primer, and replaced the ejector spring so my empties are thrown to the side again like they're supposed to instead of in front of me. Bolt wears the original gas rings and the trigger is un-adjusted since it came back from Compass Lake for modification to two stage.
The gun is cleaned after every 88 round match but I know many guys that have shot 3 or more matches in a row without anything more than some oil on the bolt.

December 12, 2012, 11:58 AM
I did try to define 'life', although I know that's murky with a component-type device like an AR, since everything is replaceable at some level of effort.

I guess just when a reasonable person would decide it's 'worn out', i.e. probably cheaper and/or less trouble in the long run to replace the rifle rather than repair it - again and again. Maybe that never happens? (Actually I would have guessed the upper would go first since it has a steel carrier riding inside it. But I know almost nothing of ARs!)

Not talking about match shooters or high use military rifles, although I'd sure enjoy hearing their input - they have special requirements and resources available.

December 12, 2012, 12:52 PM
i.e. probably cheaper and/or less trouble in the long run to replace the rifle rather than repair it - again and again. Maybe that never happens? (Actually I would have guessed the upper would go first since it has a steel carrier riding inside it. But I know almost nothing of ARs!)So probably well over 100,000 rounds, quite possibly many more than that. Basically until the pin holes are so wobbled out that the rifle won't stay together, the trigger starts to bind, etc. That's a LONG time.

Heck, the upper itself is just a replaceable part too...even though it would likely last 100,000 as well.

December 12, 2012, 04:07 PM
I don't think you need to worry about it. I change the gas rings every 5000 rounds and the extractor if it is having issues. I keep some spare parts in the grip just in case (firing pin, rings, extractor).

December 12, 2012, 05:23 PM
I have no clue how many rounds it would take to wear the pin holes on the receivers to being too sloppy to work. The 100k plus sounds like a good place to start.

As for being "worn out" when other parts go, the beauty of an AR is the modular nature. They're very servicable. Anybody thinking a shot-out barrel is grounds to replace an entire rifle is probably the same person selling a motorcycle that "needs work" because the tires are bald, the chain is stretched and they tore a hole in the seat cover. Barrels, bolts, gas rings and springs are all consumable parts IMO.

And I am one of those match shooters that rebarrels a rifle after X number of rounds. I use stainless Wilson barrel chambered by White Oak and after 3000-3500 rounds I just change them. Why? Because somewhere between 4k and 5k rounds that barrel is going to give up on the 600-yard line. (At least that's where I notice them going, when I get odd 8s that are off call I know it's beyond time.) That barrel is still good for a short-range blaster though; I imagine a chrome-lined barrel fed a diet of light weight bullets will go 15-20k rounds.

December 12, 2012, 05:30 PM
If you use Mobil 1, instead of some kind of thin, inferior lube, you're probably talking about at LEAST 100k rounds. Barrel might have to be replaced before then, but barrels are cheap. Come-to-think-of-it, ANY AR part that might ever wear out is cheap and easy to replace.

December 12, 2012, 05:35 PM
The average shooter won't fire enough rounds through his rifle to ever actually wear it out.
Service M16 rifles go waaaay over 100,000 rounds with routine maintenance and repair.
The rifles I saw that were destroyed beyond repair weren't actually shot out, they were irrepairably damaged by abuse or misuse.

Bartholomew Roberts
December 12, 2012, 06:49 PM
So probably well over 100,000 rounds, quite possibly many more than that. Basically until the pin holes are so wobbled out that the rifle won't stay together, the trigger starts to bind, etc. That's a LONG time.

i actually know someone who did this to two Colts used in testing. 160k of basically all full-auto before the pin holes egged out. We didn't get to discuss wear & tear as much as I would have liked; but he had a 5 gallon bucket filled with burst M4 barrels.

December 12, 2012, 06:55 PM
5.56 barrels usually aren't good over 20k rounds, with some going out before half that. The small bore and high velocity kills the throat.

ARs are also known for breaking bolts, either at the extractor locking lugs or the cam pin hole. They all break sooner or later. I'd be surprised if a AR bolt broke before 10k rounds and kinda surprised if it lasted 30k rounds.

Gas tubes should be replaced with the barrel, other springs, gas rings, and other parts should be replaced according to serviceability according with the TM.


December 12, 2012, 07:33 PM
The really high round count guns I've seen tend to eventually break their bolts. That is the first major component I would expect to go. More minor things likes springs, extractors, firing pins may also go. Anything north of 10K rounds and I start to suspect those parts. They may well last longer, or crap out sooner though.

Of course if one can afford to shoot 10K rounds replacing all those parts and even the bolt is financial nothing in comparison.

The next major component is likely to be the barrel. The gun will likely still function but eventual accuracy will degrade. Again as others have noted if accuracy degrade to the point it is unacceptable, the gun is easily re barreled.

There are a lot of variables in how long parts will last but I'd wager if one shot 20K rounds through an AR they would likely need to replace some part during that time.

I've seen the following preventative maintence schedule suggested:

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

December 12, 2012, 08:56 PM
5.56 barrels usually aren't good over 20k rounds, with some going out before half that. The small bore and high velocity kills the throat.The .223/5.56 is actually quite gentle on barrels. It isn't a very high pressure round and isn't burning a lot of powder. 10k is very long barrel life. You can load them hot and burn a stainless barrel out a lot quicker than that but compared to long range competition cartridges, even the hot loaded .223 loads are easy on barrels.

December 12, 2012, 09:28 PM
My departments SWAT team replaced their Colt Commandos a couple years ago. They had multiple rifles with over 70k rounds through them and they still used those rifles at work.

Side note: the SWAT team switched to POF rifles. Our departments bureaucracy says that replacing parts above a certain level requires the rifle to go back to the manufacturer. The reason they went with POF is that they are local and the owner will fix anything for them the same day. He has been known to come in on his day off/after hours to fix their rifles. Great CS from them so far.

December 13, 2012, 10:30 AM
I have 12 M4s that we use for qualifying/training with somewhere bove 30k rounds through them, half of which were on full auto.

We've recently had broken parts (bolt lugs, extractors, etc), but no appreciable loss in accuracy.

Cleaning is hit and miss, both in quality and frequency.

I would expect that a quality personally-owned M4 would last much longer.

December 13, 2012, 12:06 PM
Over the last 15 years, my ARs have shot hundreds of round and are still going strong:)

December 13, 2012, 01:15 PM
1987 Ft. Sill Oklahoma OSUT (Basic Training) Issue weapon, M16 A1.

I remember firing that thing until the gas tube turned cherry red during night fire. Then of course basic markmanship training and qualification. Cleaning- 55 gallon barrel cut in half and filled with solvent and the dreaded cleaning rod. Back then they didn't care whether you cleaned from the breech or the muzzle end. Just get the thing clean enough to pass inspection. And still accurate enough to qualify with.

God only knows how many cycles before me trained and abused the same rifle!

December 13, 2012, 01:18 PM
Barrel life is greatly improved on the AR's thanks to the chrome lining. As a plinking rifle I'd venture a guess that you'd easily be north of 10-20k rounds before needing to do any major overhaul of the rifle (probably just rebarreling, replacing extractors, etc).

If you're a dedicated competitive shooter you'll likely replace your barrel much sooner, since you'll be trying to eek out every little bit of accuracy that you can. That is no different than any other type of rifle: a recreational shooter will often get twice (or more) barrel life out of any given rifle than a competitive shooter will.

December 13, 2012, 02:58 PM
Jeff White hit the nail on the head. Heat is the biggest killer of firearm components, primarily the barrel. As long as you respect your gun and don't overheat it, it will last you a very long time. This is something I have to be careful of myself; I want to use one of my AK's for hunting, but this also means I can't do mag dumps with it. If I want to do something like that, I'd buy a cheap WASR.

Dr. Sandman
December 13, 2012, 03:26 PM
There is an old adage that goes something like "One never owns a gun, one just takes care of it for the next generation" This applies to this discussion.

I'll bet that the AVERAGE AR owner will put less than 10k rounds through the gun before it is passed on. If this is true, the AVERAGE AR own will most likely NEVER wear out an AR.

That being said, I think that a better question (esp for the NON-AVERAGE, high volume shooters that read this) would be "Has anyone ever worn out an AR? If so, how? How many rounds? Pix?"

Just some thoughts, and IMHO.

December 13, 2012, 03:27 PM
No military weapon, or for that fact, I canít think of any commercial product, is designed for an infinite life.

Structural elements, bolt, barrel, receivers, are designed with a defined service life.

In real shooting wars, the soldier is usually dead before the rifle wears out. In one book, I found that Grantís Army was experiencing 2000 causalities a day from the Wilderness to Petersburg. The Brits experienced 60,000 causalities in one day in July 1916. For war, it is more important to build rifles fast. This was appreciated during WW2 especially by the Germans who lost whole Armies in the vastness of Russia. If you look at the last ditch weapons they were making, they were having real problems arming their soldiers. The G3 rifle is a fall out of this experience, it is perhaps the first ďdisposableĒ weapon I have seen. You can look at it and see that rebuilding is not a primary or secondary priority. Building fast, building cheap, and reliable had to have been higher priorities.

So what is the service life of an AR? I donít know. Six thousand rounds is a reasonable number given a 20 year service life. Or it used to be, I have no idea how many rounds are fired per year in training, but that could be the design lifetime.

I do know that at Anniston Army Depot, one rifle is pulled from a rebuild lots and fired 6000 times. From a person who does this, there has never been a rifle that failed the test (in his tenure) and nothing breaks. You would expect that for a rifle to complete a 6000 round life test the parts would have to have more than a 6000 round life time.

I am not surprised that bolt lugs crack around 10,000 rounds, you would expect that the fatique lifetime of the structure elements to be slightly more, maybe 1.5 to 2.0 times more than the expected lifetime of the weapon.

Jeff White
December 13, 2012, 03:59 PM
The US Army gauges their rifles annually and before deployment overseas. Any parts that don't pass inspection are replaced at that time so it's hard to estimate the service life. You would need to know the maintenance history and the number of rounds it fired. Since there are no round count records kept on small arms it's just someone's best guess.

SOCOM had a project to develop a round count device for small arms but I don't know if it was ever fielded.

My estimate of 30K plus rounds on my 6920 is based on an average of 3K a year since 1998. Depending on how much time I had to train, some years I fired more and some less.

I didn't wait until I had problems to replace the extractor, I replaced it when it was visibly worn.

I have seen one bolt break at the cam pin hole. I have no idea how many rounds were fired through that rifle before it broke, as it wasn't my rifle.

If you want to maintain your AR the way the Army does, just get a copy of the 23&P TM and the gauges and give it the same annual service it gets in the Army.

The department I work for received 15 M16s through the LESO program. Yes they are all M16s, flat side uppers one even has the three prong flash hider. All of them have receivers marked AR15. Every one of them works flawlessly, they have to be 50 years old and who knows how many rounds were put through them during their service.

jolly roger
December 13, 2012, 04:23 PM
Considering 10K of Fed ball ammo is about $4000 I doubt I will worry about it too much...just get another rifle at around 50K one day :)

December 13, 2012, 05:09 PM
I would say minimum 10,000 rounds. Probably quite a bit more. It may need minor maintenance such as gas rings or maybe a new bolt after that, but should be fine. Someone with more experience will probably weigh in and give you better info.
Yah, at least 10k, probably way more, depending on barrel finish (hard chrome and melonite coatings will give you a longer life) and the way you shoot it. Slow deliberates, allowing the barrel to cool between strings are much easier on the barrel than repeated mag dumps.

December 13, 2012, 05:27 PM
Even if you NEVER clean it, you will spend thousands upon thousands of dollars in ammunition to come close to "wear it out".

Even if you low-ball the service life at only 10K rounds, that is still well over $4,000 in ammunition (assuming you buy in bulk for maximum discount).

In reality, you are probably going to spend closer to $10,000 in ammunition to shoot out most ANY AR-15 to the point it is no longer serviceable / repairable.

Worrying about a weapons "service life" is for professional armorers and Hi-Point owners. It is not something that any normal person with a quality weapon will ever have to worry about.

Dr. Sandman
December 14, 2012, 10:42 AM
Worrying about a weapons "service life" is for professional armorers and Hi-Point owners.

Har har har, esp. Hi-Point owners!

December 14, 2012, 01:57 PM
I've often thought about this myself. My AR is a left handed Stag. In the back of my mind I keep telling myself I should get a spare bolt assembly in case I wear mine out and Stag is out of the game.

Then I remember that I'll put MAYBE 500 rounds a year through it. I've had it a year and have barely done half of that simply due to work schedule/family life. I might break the bolt in a decade or two. If Stag is still cranking out Southpaw rifles (or if anyone else jumps in the game for some silly reason), I'll order some parts and fix it. If they aren't making them, I'll just slap a right handed upper on it and deal with the flying brass.

Even in the most dire TEOTWAWKI situations, most of us aren't going to wear out a rifle to the point that it isn't serviceable to us.

It is a fun exercise in understanding the modular aspect of the gun, though.

December 15, 2012, 02:36 PM
Interesting. So there appears to be a vague, unscientific-but-based-on-experience consensus that the rifles begin to show their age as they approach the 10k round range. Near that age it seems any of several things can be expected to begin breaking or showing significant wear.

So at that point, instead of waiting for the next part to fail I'd sell it and start over with a new one.

I doubt from what I've seen that I'll spend much more than the parts replacement guys over the long run, with less aggrevation and time spent fooling around AR-smithing.

Of course it's possible I'll get a new lemon, but rare, and for sure all of the old rifle is worn.

Clearly the rifle's life can be extended nearly indefinitely. So can that of nearly any machine. It's an individual decision whether it's worth the time and aggrevation. In the case of ARs, for me it's not.

December 16, 2012, 04:48 AM
December 13, 2012, 12:26 PM
Dr. Sandman
"Has anyone ever worn out an AR? If so, how? How many rounds? Pix?"

I have ARs that I have only taken to the range a couple times in 15 years, so not me.

But I have noticed that peoples worries usually can't be dispelled with facts and logic.
Worries often take on a life of their own and become self supporting.

People send me emails like this:
Colt (Diemco - Canada): milspec steel, cold hammer forged, milspec chrome lined. The hammer forging process work hardens the steel and so the barrel lasts longer than the button rifled Colt USA barrel. When Colt USA runs low on barrels, they sometimes send out AR15s with Colt (Canada) barrels, but usually not. Lasts longer than a Colt (USA) barrel.

Colt (USA), LMT and BCM: milspec steel, button rifled, milspec chrome lined.

FN (FN makes the M16 for USMC) & Daniel Defense: milspec steel, cold hammer forged, milspec chrome lined, like Colt (Canada). DD barrels are made by FN.

Noveske, Centurion: M249 barrel steel (harder and more heat resistant than M16 barrel steel), cold hammer forged, chrome lined to M249 specifications. Lasts longer than FN, BCM, DD or Colt barrels due to greater hardness and heat resistance. FN makes these barrels on order for Noveske and Centurion.

Based on the foregoing I would classify AR15 bbls as follows:

BEST: Noveske, Centurion. Centurion is here:
EXCELLENT: Daniel Defense. (Civilians cannot order FN M16 barrels or Colt (Canada) barrels).
Good: Colt (USA), BCM, LMT.

This info changes over time and it is possible that BCM and LMT have upgraded since I researched this information two years ago.

Consequently I recommend Noveske AR15s to most people who inquire, with Daniel Defense as my second choice.

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