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Aldemar
06-22-2011, 6:20 PM
OK, I just got my July issue of American Rifleman. In the Technical page #32, someone wrote in to ask about AR-15 barrel life.

Reid Coffield states that normal wear is .100" per 1000 rounds. That seems rather excessive. He further states that barrels should be replaced when wear exceeds .700" and .900".

I didn't slip my decimal point, I think he did. At least the proofreader was consistent.

xxINKxx
06-22-2011, 6:24 PM
I think like 15,000 rounds is the industry standard

Bigbird19
06-22-2011, 6:24 PM
It seems excessive and I doubt its linear as he suggests. However, I feel like he was doing that to maintain the standard 10,000 round barrel life that most manufacturers suggest.

G-forceJunkie
06-22-2011, 6:26 PM
That is measuring throat erosion, those measurments are probably how far the gauge goes in the barrel. Its a tapered rod, so the distance it travels in is a factor of the rods taper.

Aldemar
06-22-2011, 7:29 PM
Look again guys......1/10th of an inch in normal at 1,000 rounds?

I'd like to see how well a barrel shoots when it is between 7/10ths and 9/10ths of an inch worn.

He's not talking hundredths here, he's talking TENTHS

CK_32
06-22-2011, 7:31 PM
If you out shoot your barrel you shoot too much. Let's put it that way. Unless you go every weekend you won't even notice.. I head it was like 15,000 to 30,000 on average rounds and even them some can't see any (major) change in impact or groupings.

Mr_Monkeywrench
06-22-2011, 7:43 PM
Doesn't chrome lining help in this area?

Aldemar
06-22-2011, 7:52 PM
Thanks G-Force-

I just re-read the column. Indeed, he IS referring to throat wear.

That's the beauty of the internet, it allows one to look like an idiot in front of hundreds instead of just one or two.

Note to self....slow down when reading!!!!

Ahhnother8
06-22-2011, 8:38 PM
Reid Coffield states that normal wear is .100" per 1000 rounds. That seems rather excessive

It is excessive. We (highpower competitors) don't see anywhere near that much wear with heavy bullets that are pushed hard. I don't even think a 6.5x.284 has that much throat erosion.

Barrel life depends upon what you expect out of it. When the bullets keyhole, it is way past time for a new one. Ours will go 3-5,000 rounds before they are pulled off. I had one go to 10,000 that still shot well, but it was 'time'. Barrels are relatively cheap ($500) to replace.

CK_32
06-22-2011, 9:41 PM
Barrels are relatively cheap ($500) to replace.

You can get a whole new upper for that....

RugerNo1
06-22-2011, 9:49 PM
You can get a whole new upper for that....

He is referencing a much higher quality barrel than what would be in that new upper....

Think Kreiger, Bartlein, etc.

IPSICK
06-22-2011, 10:15 PM
If you out shoot your barrel you shoot too much. Let's put it that way. Unless you go every weekend you won't even notice.. I head it was like 15,000 to 30,000 on average rounds and even them some can't see any (major) change in impact or groupings.

Your not shooting enough.

tomd1584
06-22-2011, 10:25 PM
You can get a whole new upper for that....

:rofl:

mif_slim
06-22-2011, 11:14 PM
Really depend on what you call "life"....hi-power shooters call it "life" at ~4500-5000 depending and cqb/SD call it about 40k.... It's a huge gap and you decide where you at in between.

RONIN.
06-22-2011, 11:45 PM
If you out shoot your barrel you shoot too much. Let's put it that way. Unless you go every weekend you won't even notice.. I head it was like 15,000 to 30,000 on average rounds and even them some can't see any (major) change in impact or groupings. my training carbine, got 25000 rounds thru it before this deployment.. and it is my back up upper here.. it shoots just fine.. my deployment before, some of the weapons we were issued had 40k plus thru them, and groupings were still 1.5" at 100 meters.. the death of all barrels is heat.. that is why machine gun barrels get changed and allowed to cool down after heavy fire..

Doesn't chrome lining help in this area? yes, that is why the military uses chrome lined barrels..well one of the many reasons..

Your not shooting enough. exactly..

FatalKitty
06-23-2011, 12:26 AM
If you out shoot your barrel you shoot too much. Let's put it that way. Unless you go every weekend you won't even notice.. I head it was like 15,000 to 30,000 on average rounds and even them some can't see any (major) change in impact or groupings.

shoot too much? really? I had no idea there was such a thing

I shoot 2-3 times a week.... is that too much? nope.

Ak714
06-23-2011, 12:57 AM
Note to self....slow down when reading!!!!

Atleast you can read..! People like me reading is like...then there was pictures

five.five-six
06-23-2011, 12:59 AM
I think like 15,000 rounds is the industry standard

well, with 1.5" of barrel wear, there wouldn't be any barrel left :rofl2:

xrMike
06-23-2011, 10:47 AM
Can you take a shot-out barrel, cut it shorter on the breech end, re-chamber/re-throat it, and then shoot it all over again? Would such a barrel shoot as well as the original?

Put another way... Can you get "2 lives" out of a really high-end barrel by taking your shot-out rifle-length Krieger barrel and cutting it down/rechambering it and using it in a carbine upper?

Bhobbs
06-23-2011, 10:53 AM
Can you take a shot-out barrel, cut it shorter on the breech end, re-chamber/re-throat it, and then shoot it all over again? Would such a barrel shoot as well as the original?

Put another way... Can you get "2 lives" out of a really high-end barrel by taking your shot-out rifle-length Krieger barrel and cutting it down/rechambering it and using it in a carbine upper?

A lot of people have their barrels set back. I don't know if they group as good as a new barrel but I can't imagine it would. It would still group better than the shot out throat.

RugerNo1
06-23-2011, 1:08 PM
A lot of people have their barrels set back. I don't know if they group as good as a new barrel but I can't imagine it would. It would still group better than the shot out throat.

Setting back the barrel and recutting the chamber will give new life to the throat and lead, but do not expect that same amount of life as the first chambering; additionally, the accuracy may or may not resurface (a set back usually is accompanied by re-crowning the muzzle). There was still quite a bit of friction and heat working on the bore; firecracking it is called I believe.

From the smiths that I have discussed this with have stated that setting back the barrel is only worth it for the first or second set back.

JagerTroop
06-23-2011, 2:04 PM
Look again guys......1/10th of an inch in normal at 1,000 rounds?

I'd like to see how well a barrel shoots when it is between 7/10ths and 9/10ths of an inch worn.

He's not talking hundredths here, he's talking TENTHS

Lol. At 7/10ths, an AR with a M4 profile barrel becomes a SBR.

bwiese
06-23-2011, 2:47 PM
Can you take a shot-out barrel, cut it shorter on the breech end, re-chamber/re-throat it, and then shoot it all over again? Would such a barrel shoot as well as the original?

Not on a chrome-lined barrel.

On other barrels, yes -- chamber area ages far faster than actual bore.

Costwise, probably not worth the grief. Barrels ain't that expensive, and those who bought expensive bbls for their reasons wouldn't be half-assing a replacement bbl and compromising on length - they'll go get a new bbl.

RugerNo1
06-23-2011, 2:49 PM
Lol. At 7/10ths, an AR with a M4 profile barrel becomes a SBR.

This article was discussing throat erosion at the chamber end of the barrel. The barrel is not going to get shorter from use...

G-forceJunkie
06-23-2011, 7:09 PM
Right. People don't seem to be getting it. Short of a cutting torch, you not going to remove .700" out of any barrel, with any amount of shooting! We are talking about the distance the throat erosion gage moves. No how much barrel is worn or how deep the throat is. How much the gauge moved. Actual amount of metal removed from the throat, and how far forward it eroded...we are talking a few thousanths of an inch. Perhaps 10 or 20 thousanths depth wise. If your not familiar with a throat erosion gauge, it is a tapered rod with markings on it. Lets say in a new chamber the tapered rod stops on the "0" mark. You shoot 5000 rounds and now the gauge goes .500" deeper into the chamber. Nothing in your barrel is .500" bigger, only the gauge goes that deeper. The number is irrelevant, I could design a gauge that went .100" deeper every 1000 rounds, or one that only went .001 or one that went 1.000" by changing the taper.

xrMike
06-24-2011, 2:27 PM
Not on a chrome-lined barrel.

On other barrels, yes -- chamber area ages far faster than actual bore.

Costwise, probably not worth the grief. Barrels ain't that expensive, and those who bought expensive bbls for their reasons wouldn't be half-assing a replacement bbl and compromising on length - they'll go get a new bbl.Yeah, can't do that on a chrome barrel, I guess...

But let's say I have an extremely accurate WOA 20-inch match upper (with a Wilson barrel, I assume). When the groups start to open up, I will probably replace it with another WOA 20-inch upper. I was just wondering if it makes financial sense to "set back" the barrel from that 1st upper and use it in a 2nd "SPR" or "psuedo-carbine" build...

I should probably contact somebody like AR15barrels and find out the cost of a "set-back" versus a new barrel.

Thanks Bhobbs and RugerNo1 also.

Merc1138
06-24-2011, 3:53 PM
Yeah, can't do that on a chrome barrel, I guess...

But let's say I have an extremely accurate WOA 20-inch match upper (with a Wilson barrel, I assume). When the groups start to open up, I will probably replace it with another WOA 20-inch upper. I was just wondering if it makes financial sense to "set back" the barrel from that 1st upper and use it in a 2nd "SPR" or "psuedo-carbine" build...

I should probably contact somebody like AR15barrels and find out the cost of a "set-back" versus a new barrel.

Thanks Bhobbs and RugerNo1 also.

Unless you can get the work done cheap, I don't see the point compared to the cost of a new barrel(what, $300 or so from WOA?)

RugerNo1
06-24-2011, 4:14 PM
Setting back an AR barrel may not be the best choice. You would be shortening the barrel from the chamber end; therefore, you would have to mess with the gas port location and gas tube. That would be expensive work. It would be easier just to call up WOA and order another barrel.

FeuerFrei
06-24-2011, 6:16 PM
My RRA 16" AR will have passed the 15k mark next month.
It still shoots well.
I think I'll buy a new bolt and barrel when it starts to sling bullets sideways.
Standard barrel life? Kind of subjective.

GunSafari
06-24-2011, 6:27 PM
this usually isnt something the average shooter has to worry about.

in the army they come out with pallets of ammo and its shoot keep shooting till its all gone, rifles that are pushed to limits of tens of thousands of rounds or full autos are more likely to need a barrel change, hobby shooters popping off a few hundred rounds a month need not worry about this.

MUKAK
06-24-2011, 7:40 PM
this usually isnt something the average shooter has to worry about.

in the army they come out with pallets of ammo and its shoot keep shooting till its all gone, rifles that are pushed to limits of tens of thousands of rounds or full autos are more likely to need a barrel change, hobby shooters popping off a few hundred rounds a month need not worry about this.

makes perfect sense :)

PANTyRAiD
06-24-2011, 8:03 PM
What about SS barrels? I have a White Oak barrel on my AR (damn is she a good shooter too) that has about 2000 rounds or so through it...How many more before I should get a new one?

stitchnicklas
06-24-2011, 8:16 PM
stag warranty's their barrels for life according to their magazine advertisement

tvfreakarms
06-25-2011, 1:31 AM
I'm just an average shooter so i guess i won't have to worry about it for while. But i'm kind of new to the AR scene still trying to learn how to shot decent. How will you know if your barrel is going bad? I have a pof. Just curious.

hnoppenberger
06-25-2011, 1:51 AM
alot of silly talk going on. im not sure half commenting here understand how many rounds 10,000 actually is.

racky
06-25-2011, 1:57 AM
my ar has well over 15k rounds through it and still runs good. i refuse to change the barrel until it starts to keyhole. i'm actually more suprised that my bolt hasn't broken yet.

crazychinaman
06-25-2011, 10:05 AM
The standard Ar barrel is around 10,000 rounds .LWRC barrels are rated at 20,000

MaHoTex
06-25-2011, 10:10 AM
OK, I just got my July issue of American Rifleman. In the Technical page #32, someone wrote in to ask about AR-15 barrel life.

Reid Coffield states that normal wear is .100" per 1000 rounds. That seems rather excessive. He further states that barrels should be replaced when wear exceeds .700" and .900".

I didn't slip my decimal point, I think he did. At least the proofreader was consistent.

.1" is ridiculous. Does that mean the barrel opening increases by .1" / 1K round. I say impossible. a 223 round is just over double that. So with this you are saying after 1K rounds I will be able to put a .308 down the pipe. ;)

It is all good!

G-forceJunkie
06-25-2011, 10:19 AM
You didnt read the whole thread, did ya? Start with post 4 and 24.

.1" is ridiculous. Does that mean the barrel opening increases by .1" / 1K round. I say impossible. a 223 round is just over double that. So with this you are saying after 1K rounds I will be able to put a .308 down the pipe. ;)

It is all good!

MaHoTex
06-25-2011, 10:34 AM
Huh... I still do not get it... Still... It's all good. I can not wait to get to the 1K rounds and start shooting .308. :)

RugerNo1
06-25-2011, 11:57 AM
Throat erosion on the inside (http://bulletin.accurateshooter.com/2008/01/barrel-throst-erosion-revealed/) <- READ

The bore of the barrel does not get wider. To simply put it, the jump to the rifling increases (freebore) as the fire, friction, and pressure from the cartridge pushes the bullet through the barrel. Over time, those factors "erase" some of the rifling from the bore. Thus, the throat is eroded forward; not out, in, back, or sideways. The bore of the barrel will not increase in caliber.

Look back at that link again. See the slightly charred area right before the lands of the rifling start? That is the eroded throat. When a barrel is set back, a large part of that gap is removed which gives the projectile a less worn transition to the rifling in addition to a shorter jump to the rifling.

Ever read about reloaders "chasing the lands"? That means they are extending their seating depth of the bullet to reach the determined "sweet spot" of jump or jam to the rifling. When the throat is eroded to a certain point the barrel usually does not shoot as well and the bullet may not be able to be seated out that far. When you reach this point, you must decide to set back the barrel or buy a new one.

In the pursuit of the utmost accuracy and precision there is more things to pay attention to than just resizing, seating the primer, dumping powder, and seating the bullet...

PANTyRAiD
06-25-2011, 3:54 PM
In the pursuit of the utmost accuracy and precision there is more things to pay attention to than just resizing, seating the primer, dumping powder, and seating the bullet...

THIS ^

Kerplow
09-25-2011, 6:42 PM
It's a well known fact an AR barrel will chamber .50 BMG after only 100,000 rounds.

NYY
09-25-2011, 7:50 PM
a lot of shooting i would say requires barrel wear...