How Many Rounds Can You Shoot Before a Barrel Loses Accuracy and is Worn Out?

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barrel length accuracy wear worn out
Josh Wayner for TTAG

This article is something of a hybrid. It’s a candid review of a couple Faxon Firearms barrels, but it’s also an overview of what to look for when purchasing a barrel for your AR rifle.

We will be covering several topics here as they relate to these Faxon Firearms products to give you an idea of just what you can expect.

Why did I choose to go with Faxon Firearms for this article and not some other barrel maker? Well, for starters, I trust Faxon products and they have yet to fail me or refuse to stand behind their products. I have been using these barrels and other parts in my builds for years now and have a combined total of probably 50,000 rounds of various calibers fired through Faxon barrels. In all those rounds, I have never had an issue to speak of.

Barrel Life, Heat, and Accuracy

When it comes to general barrel life, my poor little 7.5” Gunner profile 300 Blackout barrel here has seen what only can be described as an unholy number of rounds in a short amount of time. I even failed to clean the barrel and the gun it was attached to for over 5,000 rounds of testing over the course of a month while doing an ammo evaluation for a large company.

During the course of that time, the barrel refused to give up and my control groups for accuracy were always the same at 2.5” at 100 yards.

A barrel doesn’t wear out in the way you may expect. I often hear that a barrel begins to lose its accuracy at about 3,000 rounds for rounds like 6.5 Creedmoor and 10,000 rounds for .308 Win and so on.

But what, exactly, is accurate barrel life?

The accurate life of a barrel is subjective and there’s no distinct definition. Some individuals and companies may try to define it, but the definition is often narrow or self-serving.

I find that 3,000 rounds of accurate barrel life for a 6.5 Creedmoor is pathetic. I have a 6.5x55mm Swedish Mauser that I typically fire about 3,000 rounds a year through and I took the top honor for the rifle and caliber at the 2017 National Matches and placed 7th overall in the Vintage match.

How is it that I can get away with shooting a 100+ year old gun with the same bullets, and I’m not restricted by a low barrel life?

barrel length accuracy wear worn out
Josh Wayner for TTAG

The answer lies in pressure and heat. Despite the fact that my prized rifle is so old, the ammunition I use is fairly low pressure and the gun never really gets that hot during firing.

Compared to something like 6.5 Creedmoor, where the pressure is very high in order to get good velocity from such a small case, you’ll see the barrel struggle to keep up at higher round counts due to the erosion that occurs near the throat and rifling lead.

The rifling itself really doesn’t wear out much, but it can slowly begin to lose definition. If you’ve ever seen some gauge an old rifle like an M1 Garand, they look at the throat and muzzle to determine how much erosion has occurred. Cleaning practices at the time took a heavy toll and powders and primers were typically corrosive, which increased the amount of wear on the steel.

As a result of cleaner powders and better modern cleaning practices, most rifle barrels today tend to wear due to the act of firing, however they still ban be damaged with harsh cleaning chemicals.

The weight of a barrel is also important in regulating heat, but not necessarily wear. A thin barrel will get hot faster than a thick one, but a thick barrel stays hot longer. A lightweight barrel like the one pictured on my rifle in this article makes the gun light and handy, but it does get very toasty after a mag or two.

For virtually all end users, there’s no real reason to have a heavy barrel on a carbine. You have probably heard that accuracy goes to hell when a thin barrel gets hot, but this isn’t entirely true. At longer ranges it certainly does matter and it matters for hunting. For man-sized targets inside 300 yards with a carbine, it really doesn’t.

Getting this thin 16” .223 Wylde (a chamber profile that can safely handle most all .223 and 5.56mm loads) Match Series Faxon barrel hot causes group sizes to open up by about 30%. That may sound horrible until you realize that means the gun goes from shooting 1” groups at 100 yards cold to shooting 1.3″ groups.

At 300 yards, that translates to groups of about 5-6” when the gun is hot, which you’ll never really notice in all practicality. If you have a 7 MOA or greater dot sight on your carbine, you’ll probably never notice at all.

barrel length accuracy wear worn out
Josh Wayner for TTAG

A hot, dirty barrel with thousands of rounds on it is often still a great barrel. My 300 Blackout barrel pictured here has shown the same accuracy on day one as it does today. It is the second barrel in that caliber I have used from Faxon and can say that they are both superior to anything else I’ve used in that they are very predictable.

I can count on those barrels to deliver in any combination of cold, hot, clean, and dirty. I wouldn’t consider any Faxon barrel I have to be worn out, despite the round count being exceedingly high. Round count isn’t a true indicator of barrel life or accuracy and I’ll elaborate on that.

Barrel Length, Weight, and Practical Accuracy

The 7.5” 300 Blackout barrel here has shot the same groups from day one. I average about 2.5” at 100 yards, which doesn’t sound especially impressive, but it is when you look at it with a trained eye.

The chase for .000001 MOA groups at 1,500 yards has led people to have a warped idea of what rifle accuracy is. There’s absolutely nothing wrong with your stock AR if it shoots 3” at 100 yards. While not particularly impressive, that’s more than serviceable for most people.

The accuracy of your AR carbine has much more to do with your interface to the gun than the gun itself. Many stock AR rifles have poor triggers and cheap stocks. Most AR (mil-spec) triggers are junk and a lot of furniture, especially some that’s sold on bargain ARs, belongs in the garbage can.

A wiggly stock plus a bad trigger makes for a bad day shooting. I try to make sure that I always have a free-float handguard on my carbines as well as a great trigger as those two things usually make a world of difference.

Running after tiny groups is a goose chase for most people. It takes money to get an AR to shoot like anything approaching a bolt gun, not to mention the knowledge that it takes to make any gun shoot well.

I’m in the process of learning how to shoot modern service rifle having spent the better part of fifteen years shooting rifles like the 1903 Springfield. It isn’t easy to sling up an AR and learn to master the nuances of a semi-auto match gun when you’ve been shot bolt actions for years. All the moving parts have an impact on your groups and, unlike a good 1903, there are lots of them.

The point here is that you’ve probably got a better gun than you realize and going with a heavy barrel won’t help you as much as you think. In fact, I’d say do the opposite and go light and short.

A 16” pencil barrel may not print ¼” groups, but your AR will be much easier to handle, carry and shoot. You really don’t lose anything. Faxon even makes barrels with integrated flash hiders and brakes that are so thin you can just slide your gas block right over them. They are very light and convenient.

What’s more, a short barrel that’s 10-14” isn’t a detriment to overall mechanical accuracy. I wrote a large piece about this concept that ran on TTAG some years ago (you can read it here).

For those who want to save a click, I’ll sum it up by saying that short barrels are no different than longer barrels when it comes to accuracy. The bullets vary in velocity for a given barrel length, which is to be expected. A short, stiff barrel is often better than a long, thin one in accuracy, but it lacks the projectile speed of a longer tube. There are really no differences for most shooters at most practical ranges.

barrel length accuracy wear worn out
Josh Wayner for TTAG

The short, stiff Faxon 300 Blackout barrel here has virtually no flex during firing, meaning that, due to being stout and rigid, it’s able to maintain accuracy over longer strings of fire while besting longer barrels with some flex.

Don’t think that I’m contradicting myself here after just telling you to go with a thin barrel. The 300 Blackout barrel I have is thin, but it’s short, thus making it stiffer in real terms. How much do you lose going from 16” to 7.5” in 300 Blackout? Probably about 100-200fps in supersonic and nothing in subsonic. There is no practical difference.

You lose more in .223/5.56, but that’s to be expected since that round wasn’t designed with micro barrels in mind. I consider 14.5-16” to be optimum for .223/5.56 since it is your best balance of length to speed with most ammo.


Just about every topic covered in this article would make for ten more detailed articles on the subject. This really just scratches the surface as far. The points you should consider for your own barrel are up to you, but you should make note of the facts and realistic end use.

A short, light barrel isn’t inaccurate nor is a heavy, long barrel always more accurate. If you go Faxon like I have, you’ll get the best of all worlds in respect to weight, accuracy, and product life. While some come close, I have yet to find barrels that are as light and as accurate which is why I recommend them if you’re looking for a replacement barrel or one for a new build.

There are a lot of myths and truisms out there that shooters love to spout when the topic of accuracy comes up (which it usually does). Velocity, accuracy, and barrel life are all subjective depending on how you intend to use your rifle.

Understand that nothing is wrong with your AR carbine if it’s not putting ten shots into .03” at 300 yards. While that would be nice, for most shooters, it’s just not something to concern yourself with so long as your gun is functioning correctly and is easy to handle.

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  1. How Many Articles Can Be Posted By TTAG While Not Noticing The Misspelling Of Accuracy? Just Askin’ For a Friend…

    • Silly rabbit…millennials don’t proofread. Instead, they believe spell check is a magical “catch all” that fixes everything…despite being told and repeatedly demonstrated over the course of their basic K-12 education that it is not. We’re lucky that the article is not one continuous, unpunctuated, entirely lower case ramble full of lazy ass “u” and “ur” type abbreviations.

    • It’s sad the first post and only contribution is about a few misspellings, the word ban instead of can being a sin, and not any useful comment on the material presented.

  2. A barrel which is too worn to be competitive in High Power Rifle competition will work great for 3-gun or any number of other games. The game defines the required accuracy.

  3. My Smith & Wesson Sport barrel should last forever(unless we have a civil war)😏How many folks actually shoot their barrel out??? It looks pretty EZ to swap an upper out…

  4. Barrels are probably a lot like drill bits. Let them get a tad too hot for their alloy and bingo….ruined in seconds.

    • I forgot to add: Never throw out any gun parts, they can be used for constructing buyback specials or confiscation dummies.

    • Jesus God, just stop opining already. No, I’m not just being mean. You don’t seem know about…anything I’ve seen you post about here, so go buy a gun if you’re old enough to, shoot a thousand rounds or so over the course of a month or two, and start reading about…everything, I guess. Then start weighing in on topics.

      Unless your barrel is getting cherry red (it’s not, btw) you are not changing the temper. There’s this thing called “critical temperature” and for the medium-soft tempers that barrel chrome-moly alloys use, it’s well above anything that would set the gun on fire. What *actually* happens, is iron alloys such as steel suffer a significant degredation of strength, abrasion, and other material properties at even several hundred degrees. So wear basically accelerates when the barrel is fired hot. High pressures & large volumes of powder both raise temperatures.

      You aren’t ruining anything “in seconds” unless you’ve got a welding mask & insulated gloves on. Metal temper will be the least of your concerns with all the near-instant cook-offs.

      • Critical temp is usually apx. where the steel goes non magnetic. Critical temp is for quenching to harden steel, not the much lesser temperatures that temper that hardness back to make a springy steel. Tempers of steels change even at a few hundred degrees F.
        Critical temp has nothing to do with tempering. That is for quenching to harden carbon steel, which in many ways is the opposite of tempering, which draws that hardness back to make it less brittle and prone to cracking.
        You might have used a wrench once or twice before. Did you read on it: “hardened and tempered steel”? They use the two terms separately because they are two very different things.

      • Typical temps I use when tempering recently hardened (or “quenched”) tool (eg, O-1, etc) or high carbon (eg, 1095 plain carbon) steel ranges from 400F to 800F. The higher the temp, the more hardness you remove.

        Things like punches I’ll temper at 400F to 450F to leave in most of the hardness; all I want to do is remove enough brittleness to keep them from shattering. For chisels, gouges and other woodworking tools, I might temper at about 600F, so they’re easier to sharpen, and the edge doesn’t break off. Screwdriver tips – maybe about 500F.

        Red-hot temperatures are used for annealing, normalizing and quenching.

        • For a gun barrel that’s typically in the ‘normalized’ condition (ie one or two notches above annealed in order to relieve stresses) yes, critical temp is pretty damn hot. Luminescent, hot. Barrels aren’t glass-hard like punches or tools, nor would you want them to be. All that heating them up to 500deg would do (think about how badly you’d have to abuse a barrel to do that; paper would readily ignite upon contact at that temp) is barely begin to stress-relieve internal tensions from forging or buttoning. That might make your zero wander a bit, heat-cycle to heat-cycle, but it wouldn’t cause your barrel to turn into a limp noodle of pig iron or whatever Billy Bob thinks he’s implying.

          The reason M2 barrels eventually shoot bullets through the sides isn’t because they melt, it’s because the steel gets so weak from the high temperature (a different phenomenon than metal temper) that the barrel sags under its own tremendous weight & recoil load and the bullets tear through the side. There’s a good chance that if you let the barrel cool even after that point, the hardness would still be similar to what you started with.

          Barrels really do get their properties from alloy, not heat treatment, because they simply aren’t very hard (even nitriding or traditional case hardening only go a couple thousandths into the metal surface, making them closer to glass-hard). What kills barrels is scraping abrasive bullets & burning powder across the leade end of the bore, when the temperature in there is already so high the metal is weakened. Even momentary pauses (‘short bursts’) allow the contact surface in there to quickly shed its thermal energy into the surrounding material, and regain that precious strength, but that too dissipates as the exterior becomes heat soaked, requiring longer recovery times or external assistance (water or active air cooling)

        • Barnowl:
          Boy, for someone who doesn’t know the difference between the hardening and the tempering of steel, you sure do use a lot of big words!
          If I were a cynical man I might think you were just out to confuse the readers by using words you don’t understand in inappropriate ways….
          Oh, wait. I am a cynical man. That makes it sooooo much easier.

    • Pretty much this. Unless you’re really shooting the hell out of your rifle you’ll not wear out the barrel of a 16 inch mforgery, the exception being if you’re doing multiple back to back msg dumps. Then again, if processing 10s of thousands of rounds of ammo is your joy, budget the price of a can of ammo every 20 cans or so for a barrel and party on. How do you know the barrel is going? If you shoot a lot you’ll know…if all you are doing is mag dumps, what difference does it make?

  5. Good article. Covered all the basics. Can’t recall ever shooting out a rifle barrel. When I was shooting competition I wore out a pistol or two. Not the barrel. The pistol. Or, at least shot them loose.

    • In the mid 80s 264 Win Mag, the Wildcats that later became 338 Lapua… We have made a lot of advancements since then

      • I hate to tell you this, but you’re off by several decades. The .264 WIN MAG goes back to at least the 1950’s. Hell, the .338 is a lot newer and that’s from the 1960’s. The ’80s was more into 7MM MAG (or Sharpe and Hart) or .257 WBY territory.

        • Ken, you’re right about the .264 Win Mag. I snorted my iced tea through my nose when I read that time line.

        • The 7mm REM MAG was all hot in the 1980s. Just the number “7” was so hot that they renamed the old .280 the 7mm Express just so they could get a “7” in there somewhere.
          I remember that because it’s why I don’t have one. They were just everywhere, so I avoided all 7s like they had plague. I think it all started with the 7mm-08.

    • Ditto. I once wore out an HK USP 40 to the point that I considered an out and out trade for a new Glock 23 a great deal and took it. That was, however, years of training and competition work. Likely in excess of 40,000 rounds. Even then the gun ran fine and shot well, I had just begun to suspect that it was through, and could have been wrong.

      Along those lines I once had an M16 that I know fired 20,000 rounds in a single summer, sometimes doing full auto dumps 6 mags at a time. It seemed fine when I relinquished it.

      Also had a MAK 47 that did something similar, entertaining children several summers to the tune of 20+k rounds, including many mag dumps, and it shot about as well new as it did when I traded it in.

      Barrel life in lowish pressure carbines that aren’t 1 moa in the first place is virtually a moot point, until you get into round count that strongly suggest you could easily afford to replace the barrel.

      What kills barrels is usually excess powder eating the throat, lousy maintenance practices or excessive heat from crazy mag dumps…and I mean a bunch in a row.

      People get this idea that since their buddies ex wife’s ex brother in laws 35 Whelan once ate a throat in less than 1k rounds, their 5k round AR must be seriously screwed up…

      For reference, I have a Chinese 7.62×39 SKS that has digested not less than 20k rounds of the cheapest crap money could buy, seldom cleaned and often mistreated. Not only does it still work, but accuracy actually improved somewhere in the middle of its abuse journey. Looking down the barrel, the rifling is nearly as crisp and sharp as a new carbine…

      Very few shooters will wear out a barrel, those who do are shooting something a lot hotter than factory 5.56×45 or 7.62×39. I mean, unless you’re cleaning your rifle with a wire brush and brake cleaner…dont clean your rifle with a wire brush and brake cleaner!

  6. You can fire more rounds before accuracy will be effected than most shooters will shoot as long as they own the rifle. This is only an area of concern for competitive precision shooters. The rifles I used at basic training were beat to hell with God knows how many rounds through them but they could still accurately hit targets at 300m. That’s good enough for most recreational shooters.

  7. Majority of shooters will never hit 30,000 rounds in a lifetime. Much less a year. And mastery is only scratched when you are standing knee deep in brass. Buy a decent name firearm, save your money, and buy all the ammo you can shoot. A well trained individual can create chaos with a bolt .22 against an army of arm chair warriors with $20,000 setups. (Thermal, air support, sat, drones- doesn’t apply).

    • You’re wasting your breath. I’ve been beating the “practice, practice, practice,” drum for years and years here. No interest.
      I guess its just too much easier to hope that the next version of tracking point will be the one that lets a computer do all the thinking for what should be men. That, or take a class and figure some of what the instructor knows will just rub off automatically.

      • There is “no interest” in practice by anyone here? You’ve polled everyone? Really??

        You come off as very myopic and arrogant when you say things like this.

        • Spot on, I even practice with my Red Rider between flipping steaks and burgers on the grill.

        • And don’t forget dry fire. It costs nothing, it can be done almost anywhere, and it’s great practice of every single shooting skill, except for recoil recovery.

      • Well, its a little bit deeper than that.
        Whenever there comes out some new gadgetry(tracking point or whatever) that everybody goes all “Ga-Ga” over, I’m always advocating put the money into ammo and practice instead.
        Because whenever you really rely on that gadget it’ll just be broke down, dead battery, or never did work in the first place(like tracking point), and THEN many ones will wish they had put the money into skills instead of gadgets.
        But, few ever listen. I just get savaged by all the tech worshipers, who have a decided tendency to then vanish when the gadget(like Hudson or tracking point) goes out of fashion(and bankrupt, again like Hudson and tracking point), when people finally figure out that it was all just marketing hype in the first place.
        Annoyed: Maybe you aren’t one of the ever-insulting tech worshiper’s, but I’ll remember you said this the next time…. just in case you ARE!

        • Ditto. Buy ammunition. Buy loading equipment. Whatever route one takes, put more money into ammo, shooting and practice.

          People are constantly ragging me asking why I, as a EE, am so down on technology on firearms. I invariably explain: “Well, eventually all these doo-dads break. Or the battery runs out.”

          The historian in me would observe that then, the shooter who depends on these gadgets is SOL – and in the worst case, now at the mercy of the shooter who knows how to shoot a rifle with just iron sights.

          Additionally, the cynic in me[*] thinks that most of this technology is just a ploy to empty the gadget-buyer’s pockets.

          [*] When one becomes a gunsmith, one becomes a cynic. It is a cause:effect relationship. There is no alternative outcome. As a gunsmith, you involuntarily see and hear so much ripe bullshit, from big-name gun makers, from doodad companies, from shooters… with such unending duration, that there is no other outcome possible.

      • Funny you should mention that … as I’ve been perusing and posting here for years and don’t recall ever seeing you post anything at all before this very day.

        I could be wrong, of course. But then I don’t really care if I am, since being preached at by an internet wundergunner is never on my to-do list.

        • It’s probably the “Knute” that’s throwing you. I’ve posted directly to you before. I started as “ken”, but then that got taken over by somebody else, so I tried “Kenneth”. That worked for years, but someone else started being “kenneth” now too.
          So, I figure “Knute” (Norwegian for “Ken”) might be OK, since likely no one else wants it. Or has even heard it pronounced properly. I left the (ken) in after to avoid confusion, which was the entire reason for the switch in the first place.

  8. So does anyone know how many rounds it takes to “wear out” a barrel?

    Say, in a varmint caliber centerfire rifle?

    Or in a .22 rimfire?

    Or in a .30-06?

    Or in any caliber?

    • I have a pistol guaranteed to shoot 2.5″ groups at 50 yards, rested, after 40,000 rounds. I’m sure you could destroy it faster if you magdump it and destroy the temper in the barrel but using some fire control should mean that it will last several lifetimes…. unless the balloon goes up before then. My dad was shooting my grandfathers 7mm WWII bolt action Krag back in the 80’s and it was still making clover leafs… just sayin’

    • There is no exact number. When your barrel gets too worn out for your particular use depends on your personal accuracy threshold under which you are unwilling to go. It’s not like the rifle shoots 0.25 moa groups until it hits some number of shots and then suddenly starts to throw 5 moa.
      As the throat erodes, the size of your groups will slowly creep larger. Some accuracy can still be salvaged by loading your ammo longer. Re-cutting the chamber and backing of the barrel further into the action for proper head space is also possible to give some rifle’s barrels a second life.

      • Setting the barrel back a turn and rechambering does work, but in my experience, by the time the gun gets to the point that the customer notices the accuracy loss and brings it in, it’s too late for that particular trick. The throat, or leade, blows out and forwards, just as all contained, high pressure gases do as they head the only way possible for them to escape. By the time the average shooter notices the drop in accuracy, the throat is usually cut deeper in than the barrel can be set back.
        Target shooters rifles though, the ones that notice a quarter MOA accuracy loss, these are the prime candidates for setting the barrel back. One just needs to notice the wear before it’s too late. After that, a new gun or a new barrel are the only solutions.

        • I cannot echo this point enough. When someone asks me how much I would charge to “set it back a turn and re-chamber” vs. “install a new barrel,” I always ask “So what group size was it holding when it first started degrading, and how many rounds have you fired since then?”

          Most of the people who want it set back by a turn have no idea on either data point. Those who do, ironically, want a new barrel and they’re not about to mess around with setting it back.

          In two rifles where customers asked about setting it back by a turn, I scoped the entire barrel in detail, not just the throat area. Holy crap… it looked like a chunk of Illinois’ roads had been transplanted into a barrel. They were both pitting – badly. One was stainless, one was chro-moly. I was amazed at the level of pitting and erosion in the stainless barrel. I sent pics of the barrel off to the customer, and we worked on a new barrel installation.

          I think I’m going to start taking a lot more pictures of bores and archiving them, now that I’m able to do that inexpensively. It would make for useful shooter education.

  9. Even my hand loaded ammo is so expensive that the cost of wearing out my upper mid range barrels is but a small fraction of the cost of the ammo needed to do so (as long as I don’t let the barrels get hot). Still, I spend a good deal of time and money working up loads that have the peak pressures as far down the barrel and as low (rarely over 50kpsi) as I can get them for a given muzzle velocity. Of course, without a strain gauge, I only have Quickload guessing what is going on in the barrel. I abhor the notion of wearing out my barrels faster than necessary. It is probably not very rational because I have never shot out a barrel on my own (only contributed to few successful team efforts in the army). Still I want to get a strain gauge system. Not knowing if my assumptions and QL are right bothers me.

  10. ‘Compared to something like 6.5 Creedmoor, where the pressure is very high in order to get good velocity from such a small case, you’ll see the barrel struggle to keep up at higher round counts due to the erosion that occurs near the throat and rifling lead.’

    Well then, add that to the list of reasons why the .260 Rem is superior to the 6.5 Creedmoor – larger case and lower pressure (slightly).

    Hate (not really) to be the spelling Nazi, but shouldn’t that be ‘leade’?

    Curious why the .308 should shoot 3+x as many rounds as the Creedmoor since the Creedmoor can’t produce any more heat and the circumference of the round is only about 85% that of the .308. Granted that should be 15% or so more heat with each shot absorbed by the leade of the barrel, but I wouldn’t think that would add up to 30% lifespan. Not saying that Josh is wrong, just wondering what the physics of it is.

    • All Modern .308 rounds have a coolant attached to the base of the round that cools the barrel down while firing. Like a reverse tracer.

      *wait for it…

      • Hmm… well expanding gasses cool rapidly, which is how modern air conditioning works…

    • Look at the barrel life of “overbore” calibers where the there is a lot of powder going down a small hole.

      6.5×55 is just starting to get into overbore territory, but the low loading pressure keeps it out.

      25-06 has long had a reputation as a barrel burner with barrel life reportedly as short as 5-600 rounds. .223 WSSM and .243 WSSM had similar reputations with .223 WSSM barrels being described as seriously eroded by 400 rounds. And for the ultimate barrel burner, there is 30-378 Weatherby. Barrels are completely shot-out in 400 rounds.

  11. Throat erosion seems to a big bugaboo. I recently read that the average time that bullets spend in a barrel over its lifetime is 6 to 10 seconds. Whoever said the game defines accuracy is relatively wise.

    • Hmm… if the average speed of the bullet in the barrel is 2000fps (it would be well over half the muzzle velocity) then the bullet would spend exactly 1/1000th of a second in a 24″ barrel. Therefore every 1000 rounds = 1 second.


      • Here’s the link:
        OFC, all just estimates as there is no way to accurately measure the projectile’s actual time up the bore, since the velocity at the muzzle is NOT the bullets velocity all the way up, but it is constantly accelerating(given a normal load and barrel length), from zero motion in regard to its starting position in the chamber, and then ever upwards toward whatever the muzzle velocity of the round is as it exits the bore.
        But that’s all covered in the article. They just call it about two milliseconds in the bore, but that’s in error on the high side. The projectile will almost certainly be in the bore less than that, so the actual barrel life is even less than these few seconds.
        It’s almost like there is a really high pressure, really hot blow torch, burning steel away as the bullet travels up the bore. Oh, wait…. That’s exactly how firearms work! I forgot for a second there that physics works…

  12. Good article. I’ve recently come to understand how much 6.5 Creedmoor pummels a barrel, which has firmly taken me out of the running for it. Looking at 6.5 Grendel, 300 BLK, or .300 WIN and building out of some Howa parts I have found an enticing deal on. Never cheap out on your barrel..

    • I’d still go with 6.5 creed. Great round.

      I’d be shocked if you shot out the barrel, though, because I’ve pretty much never heard of someone who actually has — only people being scared of doing it. YMMV.

    • No Faxon does not pay me. They just make great barrels and, having my choice of literally any products for my content, I choose the best companies to recommend based on my experience.

        • Faxon is great and you really can’t go wrong with any of their products. I have used all sorts of barrels over the years but the best performance when weight, material, and quality are concerned keeps me going back to Faxon. You can get more accurate custom made barrels, fancier barrels, carbon fiber, etc.. but they all come at a cost that is up to ten times as high but only maybe 10% better and even that is subjective when end use is considered. The average man will never shoot a faxon barrel out no matter how hard he tries.

      • not completely sure about ALL of your content, but I’m a Faxon freak as well!!! never let me down. I do most of my builds with them. great warranty as well as quality of product!

        • Sunshine orange color over Magpul FDE gives you Bakelite color. If you dye Magpul sand color it will be Hunter Orange and bright. I do that for five round hunting mags. You can find it at Michael’s or hobby lobby. Boil the water and add dye then dunk parts for about 15-20 mins or until the color is set. Stir occasionally. I use a 5 gallon boiling pot you can find at most markets. Try it out on one mag baseplate before adding more parts.

        • This is a good idea for folks with both 5.56 and .300 BLK firearms too. Dye one set of mags a bright color, and then use only those for that cartridge. That ought to keep the .300 BLK in a 5.56 chamber kabooms to a minimum.

  13. I’ve got an 03-A3 and it seems no matter how many scrubbings it gets it still shows signs of copper fouling. I’m using Hoppes #9 . I can’t can’t afford vidbro stuff ,well really can’t afford much of nothing. How many brass brushes can I run thru that barrel before I fck something up. ? I mean can I over brass brush the barrel?

    • Don’t worry about copper. It’s lead and carbon you need to remove. I never strip copper as it is part of the bearing surface of the barrel. If you totally strip a barrel, you will get consistent accuracy. I have two 1903 rifles and copper is your friend for matches and accuracy.

    • Try Frog Lube liquid for the cleaning, not lubricating. FL is has a High Specific Gravity which helps to clean the carbon and crap. Soak with it and see. Josh Warner is correct regarding the copper.

    • Like Josh said. I’ve heard of match shooters de-coppering their barrels only to have to fire a couple hundred rounds to get the accuracy back. The copper fills all the microscopic pits in the rifling and that’s why the barrels need to be broken in. So I’ve heard.

    • Possum,

      Brass is an allow of about 2/3 rds copper and 1/3 rd zinc. If you run brass brushes down your barrel and then run patches down your barrel, I suspect that you will always see a little copper (bluish-green) on your patches — which is simply a tiny bit of copper that comes off of your brass brush that you just ran down the barrel.

      If you want to aggressively strip all of the copper from your barrel, you need a solvent that is optimized for that. Hoppes makes Benchrest #9 copper solvent that seems to work. I read about other copper solvent options as well.

    • For copper fouling, reach for the black bottle. Sweets 7.62 solvent.

      Keep running patches up the barrel until the patches are almost white. The colours will start with black from powder fouling, blue from copper fouling, and eventually shades of grey to almost while. Let sit for 5 minutes and then run dry patches until the last one is shows no traces of fouling.


  14. Something not mentioned here is a factor gunsmiths call “overbore.” There are some cartridges that are “overbore” – they have a large quantity of powder stacked up behind a small diameter bullet. These cartridges tend to erode the throats of their barrels sooner.

    Examples of rounds that are “overbore:”

    – .22-250 AI
    – .243 Winchester
    – .220 Swift
    – 6.5-284
    – .25-06

    These cartridges are trying to shove a lot of burned powder down a very small diameter bore. The result is throat erosion – and you can see the result with a bore scope.

    I’ve had several .243’s come through the shop that have throats that are well worn in less than 2,000 rounds. Word from F-class competitors is that 6.5-284’s can burn up a barrel (to a point where the barrel is no longer useful in F-class competition) in as little as 1400 rounds. The .220 Swift, which used to be a favorite varmint round, has been a notorious barrel burner for decades, usually requiring a new barrel in a thousand rounds.

    I could give you a mathematical definition of “overbore,” but from my perspective, I just look at the size of the case and diameter of the bullet. From looking at lots of throats with a borescope, a guy develops an idea of which cartridges tend to burn up barrels.

    Which cartridges are easy on barrels? .308/7.62 NATO and .223/5.56 NATO are pretty easy on barrels. You might see throats start to erode depending more on how quickly they’re fired instead of total round count. The purpose-made 6mm benchrest rounds (6 BR, 6 PPC etc) are noted for very good barrel lifespans. But you can have a cartridge that has gobs and gobs of powder and it can be easy on barrels: it just has to have a big bore. I’m told by other gunsmiths who have done more work on dangerous game rifles that the .458 WinMag is very easy on barrels. The .22LR is very easy on barrels; you can have a true match barrel last at least 30,000 rounds in a .22LR. More .22’s are harmed with cleaning brushes than are burned out.

    • Dyseptic Gunsmith,

      What is your opinion on whether or not .270 Winchester is “overbore”?

      By the way your description of what causes throat erosion leads me to believe that the throat/barrels of handgun caliber rifles should last a REALLY long time — like 25,000 to 50,000 rounds. Correct?

      • I’ve never seen the level of wear that can be seen in rifle chamber throats in a handgun. The closest I’ve seen is some erosion in revolvers, when hot loads are used, and the cylinder/breech gap gets eroded from flame cutting. Sometimes, even the top strap shows some wear – but that’s in revolvers that have been fed steady diets of hot loads.

        The .270 Winchester: I’ve never seen a .270 with the number of rounds through it that I’ve seen in a) target rifles (until recently, there were really no “match” bullets available in .270), b) varmint rifles (the .270 is typically used with 130 or 150 grain bullets – I think the lightest pills I’ve seen were 110 grain V-Max bullets) or c) high firing rate rifles (eg, anything semi-auto with larger magazines).

        Most .270’s tend to get sighted in once/year, then taken hunting, and then cleaned and put away until next year. Don’t get me wrong – I think the .270 is a fine round, and I own one myself that has taken a couple species of game. I guess looking at the .270 overall, I’d say that the cartridge is slightly into the ‘overbore’ category, but I cannot remember seeing a .270 in my shop, or one that I’ve examined to buy, or one owned by a friend that’s ever made it to 1,000 rounds – and that includes pre-war Model 70’s.

        So, net:net – it could be overbore and apt to burn up barrels, but the way in which they’ve been used has not really exposed them to much wear.

        • ‘…but that’s in revolvers that have been fed steady diets of hot loads.’

          What?!? Even the Rugers?!?

        • Gov:It depends on a lot of things like powders. For instance Lilgun is known for causing throat erosion in revolvers even after not so many rounds. Not just Rugers/Smiths either, stuff like Freedom Arms too.

        • I’m sure a heavy dose of the full power stuff will accelerate the wear, but under normal use a 686 or GP100 should be good for upwards of 100,000 rounds. Although peak accuracy might wane much sooner, but unless you’re shooting out of a Ransom rest you’d probably never know.

        • GOV:
          Yup, even the Rugers. I saw a few Super Blackhawks with the forcing cone flame cut away enough to see with the naked eye, and even flame cuts into the top straps.
          OFC this was back in the 1980s when Handgun Metallic Silhouette shooting was a hot product. Indeed, those guns generally shot full power magnum loads(or more…), and lots of them. Those rams just don’t want to go over when hit with a handgun round. Gotta hit ’em on the very top edge, but that, too, is easier said than done at 200 meters with a pistol.

        • Well for the record I was being facetious with the ‘even the Rugers’ comment. On the other hand, if you’ve worn out your Super Blackhawk you’ve just spent enough on ammunition to buy many, many more Blackhawks. That’s got to be like having to buy a new car when the odometer turns over 500,000 miles.

        • Gov: Those weren’t my guns. I just dabbled in IHMSA. It was other competitors that did that to their Rugers. I always just used factory ammo and never tried to squeeze out that last dab of performance. But, like I said, I was just a dabbler. Almost everybody else was more serious than I was.
          It’s just that being known around as a gunsmith meant that I was always being asked to “just take a quick look” at this or that firearm. I didn’t get much business that way, but it did get me known as someone who would give the “straight dope” because I didn’t really want lots of gunsmithing work anyway. I live in a county of 7K population, and there just aren’t enough people to have a lot of gunsmithing work, so I’ve always taken more agricultural machining jobs than gunsmithing. Not as much fun as guns, but the pay is better.
          And I raise cattle, too, so there’s always more to do than time available to do it in.

        • Sounds like you’re living the good life, Knute. I’d be interested to know how many hot loads it took to take down a Blackhawk. But like any machine, it will eventually wear out. If these guys were all or mostly shooting Rugers that should tell you something though.

        • There were a few S&W M29s and even some semi autos and Colt SAAs, but yeah, the bulk of the guns shooting IHMSA back then were mostly blackhawks and super blackhawks. Most people didn’t keep much track of their round counts back then, but most of the ones with flame cuts in their Rugers were estimating rounds fired in the multiple thousands, with most of those being handloads beyond book maximum. Yeah, the books say never to do that, but many, maybe most, did anyway. And they were all safe. I never saw a gun blow up, except for a couple that somehow got obstructions in the bore, and that’s usually a kaboom no matter how light the load is. A steady diet of such hot loads sure played hell with those guns though. One CAN wear barrels out but it usually takes hot loads, and lots of them before it happens.
          I, personally, over the years, have seen way more damaged muzzle crowns causing accuracy problems than worn throats.

    • So, what you’re saying is that my 243 win AR-10 was probably not the best idea in the world…………….

      • Andrew Lias,

        You make an incredibly valid point. I myself was planning to build an AR-10 chambered in .243 Winchester. Now I am thinking that isn’t such a good idea since I would like to be able to put 5,000 rounds or more through it without having to change the barrel.

        Having said all that, given the ease of changing a barrel on the AR platform, that seems like the wisest choice of a rifle platform if you are going to shoot a lot of .243 Winchester.

        • You don’t have to load the cartridges as barrel burners. I have a .243WSSM AR and load my cartridges with barrel throat life in mind. I use the large volume of slower powder to produce a longer lower heat and pressure push, especially at the throat. I am not an expert in any way though. Am I certain what I am doing works? No, but lower pressure and heat at the throat especially should extend barrel accuracy. I keep the pressure under 45k, use lower heat content powder and might (according to QuickLoad) have a relatively gradual pressure curve. I push my 90gr lower start up pressure bullet to only 2,860 – 3005fps (I haven’t yet settled exactly where I want it) rather than the common 3,200-3,300fps of commercial and more common hand loads. I have gel test the impacts at velocities at which they will likely impact and it looks like they’ll do what I want. Anyway, my point is you can probably tune your ammo for the barrel life you’d like and still have some benefit from the relatively large case capacities.

        • Vic Nighthorse,

          Your solution is fantastic except for one tiny point: I do not hand load now and cannot see myself ever doing it in the foreseeable future.

          If I did hand load, I would do EXACTLY what you describe, which is an incredibly elegant approach I might add.

        • Andrew Lias,

          Well, the good news is that you can simply purchase a .308 Winchester barrel and replace your existing .243 Winchester barrel thanks to the modular nature of the AR rifle platform!

        • u_s, Vic makes a valid point though in that if you’re that worried about barrel life you should give reloading serious consideration since you’ll save more than enough in ammo to pay for that new .243 barrel. And if it makes the old barrel last longer all the better.

      • Well, I don’t have all the information to judge whether it is a good or bad idea – starting with what sort of pressures your factory ammo is loaded to.

        All I can say is that under high firing rates, it is apt to wear a barrel more quickly than an AR-10 in .308/7.62.

    • This brings up a fun question:

      In a societal collapse scenario, I would want a rifle that will shoot the most rounds possible without losing accuracy. (I would not be able to rely on acquiring new barrels or new rifles in that scenario.)

      What is the “best” caliber for a rifle that will provide the highest round count while maintaining accuracy? Of additional interest:

      I would want a rifle caliber/platform:
      — with the longest range possible
      — with the ability to take down medium size game
      — where ammunition is relatively inexpensive
      — where ammunition is readily available pretty much everywhere

      Off the top of my head, I am wondering if the old .30-30 Winchester might be that round.

      • I’d think the better barrel life would come with larger bores, like the .45-70. OFC that doesn’t give as long a range(unless one is really good at estimating unknown distances).
        .22RF is the obvious answer, since the throats of a low pressure chambering like this could go hundreds of thousands of rounds, and would likely be destroyed by careless cleaning(or other abuse) long before they ever wore out from use. But this does not give much in the way of capability to stop medium sized targets.
        I think I would say the answer is going to be something like .300 BLK or .25-45 Sharps. Anything really fits that bill if you are handloading your own rounds. But I am assuming you meant the question to only apply to factory loads, since reduced loads(I prefer to call them “tailored” for a particular use, but they are generally of less pressure than max loads) can turn ANY barrel burning cartridge into a long-lived pussycat, just by load selection.

        • Knute (Ken),

          Yes, I am thinking of factory ammunition only since one of the additional criteria is widespread availability of ammunition. Needless to say, special reduced-pressure handloads would NOT be widespread.

      • “What is the “best” caliber for a rifle that will provide the highest round count while maintaining accuracy?”

        My reply is gonna be from out in left field a bit, but anyways –

        Talking real, ‘end of days’ stuff where being on the down-low is going to be *very* important…

        .22lr, 30,000+ rounds, especially sub-sonic, and you want subsonic.

        .308 or .50 BMG, loaded subsonic. A heavy hit while fairly quiet…

      • If you’re not looking to put a scope on it a .30-30 lever gun would be the perfect round for that criteria. There’s not actually that much you can do with a .308 inside of 200 yards that you can’t do sufficiently with a .30-30. And I wouldn’t be surprised if when the SHTF it would be easier find .30-30 ammo seeing what happened to .308 ammo after Sandy Hook.

      • With those parameters, I would get a bolt action rifle with a stainless steel barrel chambered in .308 Winchester.

        • Just curious, why stainless. There’s a pretty good chance I don’t know what I’m talking about here, but I thought the right stainless alloy had the highest tinsel strength but carbon steel had higher hardness. I’d think hardness would be the key factor for throat erosion.

        • Yes, one might well think that. Intuitively, we tend to think that harder will resist wear better, but this isn’t normal wear, although projectile drag on the rifling as it travels up the bore is a factor. But I (and lots of other smiths too), tend to believe its the heat and pressure that cuts the steel away like a super sized oxyacetylene torch.
          So, IOWs, it’s the heat and corrosion resistance of stainless steel that we desire for this purpose, and not the hardness.

        • I was actually wondering if stainless dispersed the heat better but I just did a search and found that SS has lower thermal conductivity than carbon steel. Maybe it doesn’t absorb the heat and more heat gets blasted out the muzzle?

          Also, I wonder if anyone has tried titanium for a gun barrel since it’s melting temperature is about twice that of steel. Have no idea if it would be suitable though.

        • Stainless has higher levels of chromium in the alloy, which helps resist wear longer.

          This brings up a favorite topic of mine: metallurgy. Most people have no flippin’ clue what goes into metallurgy.

          White guys invented it. The rest of the world barely understands it. The Chinese have sacrificed 10’s of millions of lives just trying to perform cargo cult imitations of the white man’s learning on this subject. We white guys who are tired of listening to SJW whinging about “social justice” should demand that everyone who doesn’t understand steel immediately give all their steel up. They’re guilty of cultural appropriation, and they need to stop it.

          Here’s the secret for people who want to start to understand this topic: Start with answering the question “What is steel?”

          Everyone in any modern society depends on steel, but 98% of people cannot even tell you what steel is – and isn’t. Hell, most people still think such a thing as wrought iron is still made in the US today.

          When I teach students the basics of steel, you can see the “ah-ha!” moment when they really understand the basics of steel. It takes only about six hours of instruction at the blackboard and in the shop. I can teach students the secrets of steel in a machine shop, or a welding shop. or over a blacksmith’s anvil. Hell, I could teach the secret lessons of steel in a hardware store next to a sink.

          Modern schools, however, being run by females and feminized men, have completely dropped the ball in teaching modern students one of the most important areas of modern knowledge – perhaps one of the single most important advances of the modern civilization, and most people today, even with PhD’s, don’t know anything about it. The lessons of history are simple: Those who fail to understand the secrets of steel will give up their land, money and women to those who do understand steel.

          It’s a wonderful moment when I see understanding of steel happen in students.

        • Hmm… while I’m quite sure that it was white guys from a place called ‘Demascus’ that invented steel (or was it India?), when it comes to metallurgy in general I’m pretty sure that the guys who invented bronze were more of an olive complection. Of course I think those might have been the same guys who gave us algebra, so perhaps they don’t deserve any accolades.

  15. Over heating a barrel can kill it in minutes. Of course to do that we are speaking of full auto fire. In semi-auto fire it depends on the caliber, amount of powder, and pressure. I twice got 10,000 rounds out of a .223 and usually got 6,000 to 8000 out of a .308 when I used to shoot in competition. I got only 800 rounds out of a 7mm STW. I got only 900 out of a .220 swift, and 1000 out of a 22-250 and only 2,000 out of a 6mm ppc and ditto for a .243 winchester. I got 8,000 out of several 30-06 rifles used in competition.

    If you are a once a year hunter you will never wear a barrel throat out but if you are in competition be aware that you barrel throat is not long for this world as a season or two of competition usually cooks most throats out.

  16. All this is why I like cartridges like .38-55, .45-70, ,45 colt, with cast lead and black powder. As long as you clean them, barrels last indefinitely. .30-06 is another one that loves cast.

  17. just about any over-bore ,like the 220 swift or the 270 gibbs conversion with velositys over 4000 fps, will go shotgun after about 1000 rounds . the faster the load ,the more te sparks out of the bbl . is a good indicator of rifleing going by-by. nasa did some experiments with way-overbore in the 60’s the 22-378, and the 30-378 both were spark-shooters ,some loads were in the 7500fps range ,very hot loads. only solid bullets would work with them.standard hornady spitzer would blow-up about 150 yards out . definitely not practical..but they would make a bolilng ball go up in smoke.

  18. I’ve always heard a good 5.56 mm NATO barrel will last about 20K rounds. Any truth to that oft repeated statistic?

    • Mark,

      Someone tested multiple 5.56 NATO barrels with multiple loads. If I remember correctly:
      (1) Inexpensive Russian 5.56 NATO ammunition wore out the barrels pretty fast, at something like 5,000 rounds.
      (2) Quality 5.56 NATO ammunition wore out the barrels at something like 15,000 rounds.

      Now, here is something interesting: 15,000 rounds of quality 5.56 NATO ammunition costs a LOT more than inexpensive Russian 5.56 NATO ammunition. In fact the cost difference is well beyond the cost of two replacement barrels! That means you can shoot 15,000 rounds of inexpensive Russian ammunition, replace your barrel twice (for a total of three barrels including the original factory barrel), and still have money left over.

      So, whether or not it makes more sense to shoot inexpensive Russian ammunition and replace your barrels much frequently depends on your application. If you are only concerned about having a lot of fun plinking, go the route of inexpensive Russian ammunition route and two replacement barrels. If you want a rifle that you can depend on for accuracy easily to 10,000 rounds without having to worry about lugging around a replacement barrel, then go the route of quality ammunition.

      Edit: it looks like the ammunition distributor Lucky Gunner ran that test. You can review it here:
      www . luckygunner . com/labs/brass-vs-steel-cased-ammo/

      (Note: I added spaces between the text strings and the periods in that link to the Lucky Gunner test to ensure that it would post here. Remove the spaces before trying to go to their website.)

      • If you want a rifle that you can depend on for accuracy PERIOD, then go the route of quality ammunition.

        • Which is why I said above “bolt action, .308 rifle, stainless barrel.”

          Feed it Federal Gold Medal Match .308 168 grain ammo and call it done. Buy it by the case, and at a buck a round, Bob’s your uncle.

  19. And how many times may a rifle be shot
    Before it’s accuracy is gone
    The answer my friend
    Is blowing in the wind
    The answer is blowing in the wind…

        • Now that you bring it up, yes, I am. Dylan, like Carlin was a phoney ‘rebel’. 2 rich dudes railing against the system that made them rich. And they were only railing to get richer. They found an audience of sheeple and played to that flock.

    • Yeah, the answer to this one is blowing in the wind, because nobody really knows exactly what goes on in that millisecond between primer ignition and the bullet exiting the muzzle. We have some really good guesses, based on a considerable body of evidence, but what exactly is occurring in that millisecond is just not fully known.
      For example, judging by case capacity and bore diameter, the .50 BMG is one of the highest overbore cartridges in existence in the realm of small arms, and such burn barrels like candy, but it doesn’t. We know from experience it lasts a long time before the barrel wears out. Barring shooting out a full auto from excessive firing time. Get a barrel too hot and it fails. End of story.
      In theory, the .338 WIN MAG should be much easier on barrels than a .50 BMG, but we know it’s not. Why? Nobody really knows, although theories abound. But none that have stuck. Not yet anyway. At least, not that I’m aware of.

      • Well, the .50 would be eroding the barrel faster if we’re talking of the .50 using a barrel made the same way the typical .338 barrel is.

        .50 M2 and M3 barrels have a stellite liner in the chamber/throat area. It’s harder than barrel steel ever will be. Stellite resists flame-cutting and abrasive wear very well. The way these stellite-lined barrels are made is almost witchcraft – they make, rifle and hone the liner, then they heat up the previously rifled barrel, slip in the liner, get the rifling grooves to line up, and then cool the barrel to shrink it onto the stellite liner.

        Then the mil-spec M2 HB barrel is made from an alloy not used in the civilian rifle barrel market. The spec is MIL-S-46047, a special alloy with higher levels of vandium than 4140 and 416, which are the typical barrel alloys.

        These barrels are also honed to incredible levels of straightness and roundness after gundrilling with special Sunnen hones.

  20. Some real good discussion going on in the comments. I wish DS would write some articles, his knowledge is vast and I like the way he explains things.

  21. Help. Is the rifle pictured below the title with the orange stock a Faxon AR or something else.
    My thanks in advance for any help you can give.

    • It is a lightweight parts build with magpul stocks I dyed to look like bakelite.

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