Barrel life question, regarding # of rounds

Had no luck searching, but I was just wondering what is the general consensus of when a rifle barrel is "worn out" and needing replacing?

For instance, if you have a generic AR with a chrome lined barrel, or...

a generic AR with a NON chrome lined barrel, or...

even a pistol caliber rifle, like a Sub 2000, 9mm AR, or even a HiPoint, or the like?

Assuming you never using any corrosive or steel cased ammo, and only FMJ...

Just curious...

I saw a show yesterday on the Sportsman Channel and a guy had a 2nd Gen Sub 2000 that he said he'd ran 13,000 rounds through it, and had only cleaned it twice...Is that expected, normal, or a minority?

Would the guesstimate be different for a range toy/plinker, versus a hunting rifle that might only fire 2 shots a year? I mean, that guy may consider 1,000 rounds through his high dollar rifle, in it's lifetime, a lot...

the experts can correct me if i am wrong but if you are running an AR as a precision gun and keeping sub-moa groups, the round count will be much much less than a standard tactical AR rifle setup. For precision i will leave that alone for the precision guys on here. As for basic functioning of the rifle, what i've been told is that the gas hole in the barrel will start to form an egg shape (as opposed to the original circle) over time (the wear starting to become noticeable supposedly around 8,000 rounds ) due to corrosive nature of gas and compounds from firing. once that starts to happen, the gun can start to have cycling issues. As for the barrel itself, one of my clients (gun manufacturer) has hundreds of thousands of rounds through their Ser #1 rifle (full auto). They have changed firing pins that have worn down but still the original barrel on the firearm (piston operated system so the egg shaping of gas hole does not impact functionality). The malfunctions have been solely magazine issues and firing pins that have worn down significantly. I don't think the precision of it has been tested at distance in a while other than on the test range on-site for demo purposes which still has POI where the Aimpoint red dot is placed. I would be curious how accurate it is at distance at this point but still cycles perfectly fine. I think you will see huge variance with different barrel manufacturers but i've seen 8,000 as the number a few times (I've seen a lot lower also). Again, on a precision gun i would expect 1,000 rounds would be a lot. Disclaimer - This is just information picked up from people in the business and I do not have first-hand knowledge so if anyone has experience that contradicts this, i will yield. I do think this is a good question though OP.

Thank you very much for the detailed reply.

Not really concerned too much with precision shooting, as I am far from that... It would be interesting to hear their feedback though.

Just more curious about your basic shooter...hobbyist, range shooter, plinker, varmint hunting guys and gals.

There are too many factors.

The materials and the methods used to make the barrel, and what treatment is applied will all effect the wear differently. Projectile types and powders seem to have a variable as well.

The rifling is the last thing that will go in a rifled barrel. The throat will erode and so will the muzzle long before your eye will see anything. You need erosion gauges and a bore scope to observe said wear.

A shot out barrel will generally be safe, it just wont shoot well.

In my experience, cleaning too often accelerates wear.

Ill give you one example. I have seen examples of certain AR and AK barrels start to keyhole in under 5k rounds, and these are not "match" barrels.

The high pressure and high velocity rounds will burn barrels far quicker than anything else. Pistol caliber barrels last a really long time, especially if chromed or nitrided like many are. I ran into a guy a few months ago who had a Gen 4 Glock 17 with 65k rounds of steel case 9mm through it. He said it was starting to get a little shot out, but it still had plenty of life in it.

According to Battlefield Vegas, their WASR AK barrels have six digit round counts (at full auto too) and they're not shot out.
http://www.thefirearmblog.com/blog/2015/06/03/how-many-rounds-can-an-ak-fire-before-it-breaks-down/

If you look at the Lucky Gunner 10k rd AR test, they fired an AR with Federal brass as a control. They still had acceptable accuracy at 10k rounds, even though the chrome was cracked, the throat was eroded a good bit, and the gas port had quite a bit of erosion.
http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/

Ballistic Radio did a 20k round test of an KAC SR15.. It still had pretty good accuracy at the end.
http://ballisticradio.com/endurance-tests/kac-sr-15-mod-2/

Here's an interesting article on barrel break in that mentions a GA Precision rifle that had over 120k rounds through the barrel, and it was still sub-MOA. There was 4" of rifling missing from the throat, which must have dropped velocity quite a bit, but it was still accurate.
http://www.scout.com/military/snipers-hide/story/1696627-barrel-break-in-what-i-have-learned

From a competition/precision shooter's perspective it depends on the barrel. The general rule of thumb for .223 is 3,000rds for a Wilson barrel and 5,000rds for a premium barrel such as Kreiger. Other calibers will have different life spans. I did clean the 600 yd target with a Kreiger barrel that had a logged 13,000 rds through it though. That barrel was an exception to the rule. Score was 200-8X, I replaced it after that match since the X count was not up to par and called good shots that should have been in the X ring leaked out into the 10 ring.. A top level competition shooter will replace the barrel when ever the X count drops off regardless of round count. The first barrel on my 6XC went south after only 1800 rds., it should have lasted at least 2500 rds. It was a Schneider barrel and they are not cheap. Shooters with lower skill level will not notice the fall off as quickly as a High Master and generally attribute the drop off to making bad shots. There is a point where your skill level is good enough to know the difference between a bad shot and a barrels accuracy level beginning to fail. Many people cite test results that show barrels holding accuracy for tens of thousands of rounds but, they are not doing it at distance. Their standards of accuracy are far less than mine as well.

clandestine said:

There are too many factors.

The materials and the methods used to make the barrel, and what treatment is applied will all effect the wear differently. Projectile types and powders seem to have a variable as well.

The rifling is the last thing that will go in a rifled barrel. The throat will erode and so will the muzzle long before your eye will see anything. You need erosion gauges and a bore scope to observe said wear.

A shot out barrel will generally be safe, it just wont shoot well.

In my experience, cleaning too often accelerates wear.

Ill give you one example. I have seen examples of certain AR and AK barrels start to keyhole in under 5k rounds, and these are not "match" barrels.

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To the OP, look for the Luck Gunner article. They did a great test on steel cased vs brass cased ammo in 16" ARs with identical hardware setups. If I recall, they used chrome lined barrel and shot them HARD. Like mag dumps. Cleaned them every 1k. Tested every 2.5k. Total strip down at 5k and shot till 10k.

I believe the bimetallic steel jacketed ammo roughly burned out the barrels by around 7-8k rounds. This is when key holing started, velocity dropped a lot, etc. the one shot with federal AE223 brass case, gilding jacketed ammo was going strong at 10k rounds. It showed a loss of accuracy and velocity, but well within "military and or plinking" use acceptable numbers. Like it had dropped from about 2MOA to about 3MOA and had lost about 150fps or so of velocity. Compared to the steelie shot rifles that had lost about 300fps and were shooting about 5-6moa.

Those are worst case tests, not real world as mag dumps heat the barrel up a LOT which accelerates wear a LOT.

Also on an AR it is pretty easy to change a barrel in most cases. Both my ARs have NSR free float hand guards and I could probably swap a barrel in 5 minutes. Call it 30 cause it can be a pain to get the handguard lines back up.

Figure your agerage range worry AR spitting bimetallic rounds all its life is probably a 10k barrel life rifle. Brass, probably a 15-20k barrel. Stainless steel, dunno, 1/2-2/3rds that? (SS is softer, but in part because of that it is easier to form, which means it is easier to make an accurate barrel).

For others, really depends so much. A pistol is going to have a VERY long life. The lower the pressures and the slower the round, the less barrel wear there is. A .22-250 probably is lucky to see 1500 rounds before needing to rebarrel. A 22lr could probably see 50k rounds before the barrel was shot.

dist1646 said:

From a competition/precision shooter's perspective it depends on the barrel. The general rule of thumb for .223 is 3,000rds for a Wilson barrel and 5,000rds for a premium barrel such as Kreiger. Other calibers will have different life spans. I did clean the 600 yd target with a Kreiger barrel that had a logged 13,000 rds through it though. That barrel was an exception to the rule. Score was 200-8X, I replaced it after that match since the X count was not up to par and called good shots that should have been in the X ring leaked out into the 10 ring.. A top level competition shooter will replace the barrel when ever the X count drops off regardless of round count. The first barrel on my 6XC went south after only 1800 rds., it should have lasted at least 2500 rds. It was a Schneider barrel and they are not cheap. Shooters with lower skill level will not notice the fall off as quickly as a High Master and generally attribute the drop off to making bad shots. There is a point where your skill level is good enough to know the difference between a bad shot and a barrels accuracy level beginning to fail. Many people cite test results that show barrels holding accuracy for tens of thousands of rounds but, they are not doing it at distance. Their standards of accuracy are far less than mine as well.

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Which is where standards come in. Depends on what yours are. Yours are extremely high, but based on what you are doing, that is understandable. For most typical shooters though, accuracy sneaking up from 1MOA to 2MOA is probably acceptable before replacing a barrel and it might mean 3x the round counts you find acceptable before replacing a barrel.

Certainly if I was a competition shooter I'd probably have really high standards as well. Mine are more relaxed. A 2MOA plinker is just fine.

So many variables....too many to quantify numbers.

Usage? 3000 rounds of .223, fired a round a minute, or a mag a minute? Same round count both ways, but a huge difference in heat generated. One barrel never got hot. The other you can fry eggs on.

Expectations? A new .25 MOA or better barrel that later becomes a 1 MOA barrel might well be seen by a hunter as being a tack driver. You might find a serious bench rest competitor with a dozen such barrels in his garden, with half being used for bean poles, and the other half being used for tomato stakes.

That said, you can know that barrels that are typically being kept cool are going to last longer than those that aren't. Same can be said for your cartridge selection. You can crank velocity or keep it moderate, by either cartridge selection or load selection. The overbores as an example will surely sizzle, just not for as long with regard to barrel life.

Trade offs to be made, and expectations to be met. Only one of which is comparative barrel life. There's no free lunch.

lazarus said:

To the OP, look for the Luck Gunner article.

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It's right here:

http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/#reliable

Great test, and instructive reading.

Bucha variables as well discussed.

I would expand Dist1646's comment in skill of shooter to also include the shoiter's requirements/ expectations of particular rifle. A top level benchrest shooter may also have a CQB type blasting carbine with different expectations.

For a shooter of Dist1646's ilk, a .25in bbl that deteriorates to .50 would be hopelessly shot out. For high volume carbine shooting primarily within 100yds, and usually at quasi-pistol distance 3moa is fine. That Los Vegas range has an accuracy standard of bullet impacting point first at 15yds . I would speculate the gas port would be erroded enough to effect reliability before accuracy would be too bad to make center mass sized groups at 15yds.

I will put extra emphasis on bbl temperatures. Three shot groups 15min apart will have order of magnatude longer life than mag dumps.

From my experience until the barrel doesn't pass the Headspace and or the using a Barrel Gauge test.

Because in the Corps you PFI 'd every Rifle prior to a shoot or Range Detail which involves gauging... Civilian Not so much...

Also Civilian doesn't have Full-Auto capability, so that is a factor.

I think limiting your cleaning cycle is not a good idea...imo...I mean I am BW to clean after every use...

Thanks for all the great feedback guys. I got some reading to do.

What brought the whole question on, was me and a co-worker just having a BS session. He has what I would call a well taken care of rifle, for sale, that he has shot nothing but FMJ ammo through it, (800 rounds or so). An inquirer made a lowball offer because, in his/her words, it was a "well worn" barrel...which I thought was ridiculous, as did he.

I could understand possibly excessive wear in/on a rifle that had shot nothing but corrosive, steel cased ammo, and was not maintained, but not gun that has shot decent ammo, and has never even been shot outside.

Thanks again for all the replies. I'm sure they'll help others, as well as having given me a very detailed explanation.

Unless it was 800 rounds of rocks, or it's a $20,000 rifle, 800 rounds is not "well worn."

Hawkeye said:

Unless it was 800 rounds of rocks, or it's a $20,000 rifle, 800 rounds is not "well worn."

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That was my thoughts, exactly. I just wanted to see what the people here, with much more gun knowledge than I have, had to say.

Steel Case or Aluminum or Brass doesn't effect wear because the case is in the Chamber of the Barrel.

FMJ, JHP, or SPHP or any other type bullet will all have the same effect on the barrel as in wear.

But you need to consider that a Firearm utilizes and explosion to propel a projectile so your material needs to be dense and strong enough to mitigate the explosion and fatigue from that reaction and be safe to use fro extended periods of time...

880 rounds is drop I the bucket consider this a Rifle Range Detail (Back in my day in the Corps) you used about 150 rounds the first day, double strings and then 100 rounds a day for 4 days, so 550 rounds in one week. Present day might be more because the type of Range Training has changed...

800 rds. may not be well worn but, it is certainly worthy of being considered in price negotiation.