I think a guy could say that the average barrel life for middle of the road velocities for most calibers is around 3000 rounds.

A good number for the time it takes fo a bullet to exit the barrel after the primer ignites the charge is .0025 seconds.

This means that average barrel life is 7.5 seconds.

Wayne Simpson stated in an article in (I think) the Nosler reloading manual that he had a .220 Swift that had passed the 5000 rounds mark at full bore velocities and was still shooting under a MOA

The barrel life statistic varies quite a bit depending on who you ask and how the barrel was cared for.

That said....if a .220 Swift exits at 4,000 FPS and the barrel is 24" and distance= V times T

then average velocity (approximately) is 2000 FPS (as it starts from 0.0 and ends at 4,000)
therefore time = .001 seconds.

At .0025 seconds you must be shooting one of those much slower Elk guns....

Given all this.....Mr Simpson's .220 Swift has lasted five seconds and still shooting fine.

Is 2.5 seconds worth arguing over?

Barrel life?

I have a barrel that is 112 years old on a 30/40 Krag Carbine...and still is a tack driver...

A reference chart only, not meant to be exact

quote:

Originally posted by vapodog:
Wayne Simpson stated in an article in (I think) the Nosler reloading manual that he had a .220 Swift that had passed the 5000 rounds mark at full bore velocities and was still shooting under a MOA

The barrel life statistic varies quite a bit depending on who you ask and how the barrel was cared for.

That said....if a .220 Swift exits at 4,000 FPS and the barrel is 24" and distance= V times T

then average velocity (approximately) is 2000 FPS (as it starts from 0.0 and ends at 4,000)
therefore time = .001 seconds.

At .0025 seconds you must be shooting one of those much slower Elk guns....

Given all this.....Mr Simpson's .220 Swift has lasted five seconds and still shooting fine.

Is 2.5 seconds worth arguing over?

V-dog
I assisted a few college boys with their "Capstone Project" and that involved firing a number of rounds from an instrumented barrel (they were looking at pressure&velocity change with ammo temperature as the variable). They were able to borrow a nice data acquisition package from a former student (one of those $10K "black box" units). Running at some 20,000 data points/second, we were even able to see the barrels reaction to a dry fire.

Anyway, from first pressure (primer ignition) to pressure fall (bullet exit) off we were looking at something in the .004-.005sec range with the MV averaging 3000fps over the course of some 150 rounds. Barrel time for the bullet would be shorter, of course, due to the amount of time it takes for the pressure to climb to the release pressure, and the amount of time it takes to clear the gas from the muzzle

Interesting subject.

We have a custom built 308 Winchester, on a Remington 700, and a Dan Lilja barrel.

It is the rifle everyone shoots when they come to our range. Mostly using surplus military ammo.

The inside of the barrel looks like an elephant skin!

At an absolute minimum, this rifle has had at least 40,000 rounds through it.

Just out of interest after reading this thread, I just shot it using locally made match ammo with Sierra MK 155 grain bullets.

It shot well below an inch for 5 shots at 100 yards.

I will take a photo of this group and post it tomorrow, as others are using the range right now.

I think there are so many variables for this, that one cannot state with any sort of certainty how long a certain barrel can remain usable.

I think we're talking about two different ideas here.

Interestingly enough, we did some pressure barrel testing some years ago with two pressure sensors ... one at the mouth of the chamber and one at the gas port distance for a 20" AR barrel. Rise time of the piezoelectric sensors was in the slightly sub-microsecond range.

A good estimate of bore residence time was shown to be 0.0035 seconds (3.5 milliseconds).

In terms of accuracy versus number of rounds fired, my memory is that barrel life is generally greater as the diameter of the projectile increases assuming a similar overbore for the cartridge.

There are a lot of factors in barrel life. The top two are cartridge and fabrication method. Cartridge is easy - hotter calibers yield shorter barrel life. Fabrication method is equally important, with buton rifled barrels being the least durable, cut rifled next, and finally hammer forged barrels being the most durable. Then you can complicate these with chrome lining and such.

quote:

Fabrication method is equally important, with buton rifled barrels being the least durable, cut rifled next, and finally hammer forged barrels being the most durable.

Any idea why this is???....or maybe you have a link to information about this???....This is news to me as it's the first I've read about mfg method related to barrel life.

Another consideration is the definition of accuray-it is not uncommon to have an AR NM barrel last well inot the 5-8k range, but iften a barel which will still shoot sub-mi nute groups at 100yds, will not reliably hold the 10 ring of the MR target (2 MOA) at 600yds. These uppers normally become short course or practice uppers. First indication of a barrel gone south is unexplainable flyers at 600.

Cleaning procedures are often much more detrimental to accuracy than actual firing....

quote:

Originally posted by vapodog:

quote:

Fabrication method is equally important, with buton rifled barrels being the least durable, cut rifled next, and finally hammer forged barrels being the most durable.

Any idea why this is???....or maybe you have a link to information about this???....This is news to me as it's the first I've read about mfg method related to barrel life.

Interesting and I would like to know as well.

I've been told by a couple of long range shooters that after 3-4K rounds they have had guns which would still group pretty well at shorter distances, say out to 300yds or so, but that they got fliers at 500+. I believe that throat erosion is the biggest cuase of this.

Sometimes a barrel will still have good rifling but cartgs like 243win or 25-06 can burn a throat out when not taken care of. It is interesting on what wide ranges of longevity there is from 3k up to 40K!!! I think that the level of accuracy desired has a lot to do with twhat is acceptable. A gun that shoots 1" groups after 10K rounds is pretty good, but has still lost a lot if it was .25" shooter when new.

I agree.

What is acceptable accuracy to some may not be for others. Acceptable accuracy for a hunting rifle won't be the same for a target gun

I've heard of bench rest competitors rebarreling after 300 rounds!

quote:

Originally posted by guncurtis2:
I've been told by a couple of long range shooters that after 3-4K rounds they have had guns which would still group pretty well at shorter distances, say out to 300yds or so, but that they got fliers at 500+. I believe that throat erosion is the biggest cuase of this.

Sometimes a barrel will still have good rifling but cartgs like 243win or 25-06 can burn a throat out when not taken care of. It is interesting on what wide ranges of longevity there is from 3k up to 40K!!! I think that the level of accuracy desired has a lot to do with twhat is acceptable. A gun that shoots 1" groups after 10K rounds is pretty good, but has still lost a lot if it was .25" shooter when new.

A flier is not likely the result of a degrading barrel but more likely the result of a defective bullet, gust of wind or human error. These are the three ever changing variables directly effecting accuracy so it not practical to blame the eroding barrel for a flier. If the groups become measurably larger then we can say the barrel is waring out but it is hard to associate a flier with it.

As promised, here is the rifle I am talking about, and the targets I shot with it yesterday.

I have no idea how many rounds have been fired through it since it was last cleaned.

This rifle is not really looked after at all.

The photos are of match ammo made locally, military ammo, and the headstamp of the military ammo I used.

Great Saeed!

I've heard that Remington has a .308 at their proofing facility that has a similar amount of rounds through it with MOA accuracy

Cartridge intensity plays a role.

I have rebarrelled a 22-250VS and a .223 XR-100 and while I don't count the number of rounds each rifle had shot, both rifles followed the same pattern. The groups would get gradually bigger and you would start getting unexplainable flyers. At first, of course, the flyer would merely bulge the side of the group but after a bit, the flyer would detach into a free standing hole in the target.

wasbeeman

Have you adjusted seating depth as the throat wears and moves forward?

quote:

Originally posted by rcamuglia:
wasbeeman

Have you adjusted seating depth as the throat wears and moves forward?

Somtimes, particularly with heavier barrels, you can even turn a barrel back a few threads or lop off the entire threaded portion and recut threads then rechamber and headspace. If the rifling is still good this gives you a fresh throat to shoot through.

quote:

Originally posted by rcamuglia:
wasbeeman

Have you adjusted seating depth as the throat wears and moves forward?

On the 22-250, each spring I would re-set my COL and rework my load, using a Chrony, until I was back to the original velocity. I think I got several more years of Pdog and target shooting by doing that. When I finally sent it off to be re-barreled, my powder load was admittedly out of the book and I didn't have a lot of bullet in the neck.

The .223 is XR-100 and is the most accurate rifle I have owned. My col had the bullet set out a good bit to begin with but I jimmed around with it some but the thing was that the group had grown also. When you shoot a group that would measure .25 and it grows to .5 because of a flyer, it can really hurt your feelings. The smith suggested that I set the barrel back and inch but I decided to go ahead with the re-barrel. It's still at the smith's.

It's gonna be interesting. This is my first rifle to be re-barreled to anything other than factory specs. I sent the smith two fired cases and two loaded rounds to work from. Considering that I have shot a (1) group of .111 with this rifle and it has consistantly shot into the .2s, I'm looking forward to shooting it with the aftermarket barrel.

quote:

Originally posted by vapodog:

quote:

Fabrication method is equally important, with buton rifled barrels being the least durable, cut rifled next, and finally hammer forged barrels being the most durable.

Any idea why this is???....or maybe you have a link to information about this???....This is news to me as it's the first I've read about mfg method related to barrel life.

I thought it was pretty common knowledge. It is, at least it is among competitive shooters.

Some features that make Cut Rifled barrels more durable than Button Rifled are that A)the grooves are usually deeper B) button rifled bores expand when you contour the barrel and C) It's easier to get a tapered bore with Cut Rifling.

Hammer forging toughens the steel, along with allowing deep grooves or grooves of nearly any design, including polygonal (such as on HK machinegun barrels). Hammer forged barrels can also be forged with a tapered bore which also enhances the accurate life. Hammer Forged bores shrink when you contour them too.

You won't find many serious competitors who will take a 3,000 or more round count button rifled barrel to Perry - it's too risky that the barrel will die in the middle of the National Championships. You will, however, see serious competitors take a cut rifled barrel to The Nationals with 4,000 rounds down range.

I thought everyone knew this, it's been researched pretty thoroughly by various military's. Unfortunately, I don't see these studies on-line, but here are a few links to get you started in your own research.
Armalon Barrels
Precision Shooting on HF
General Barrel Article
Bravo Co. HF Barrels

BECoole,
I shoot competition and I disagree with you. I use both button and cut rifle barrels. After being in several barrel shops I will say the choke[taper] inside a barrel is lapped into it and not cut that way.
I doubt that you will find many military rifles shooting either button or cut rifle barrels.
Butch

quote:

Originally posted by BECoole:

quote:

Originally posted by vapodog:

quote:

Fabrication method is equally important, with buton rifled barrels being the least durable, cut rifled next, and finally hammer forged barrels being the most durable.

Any idea why this is???....or maybe you have a link to information about this???....This is news to me as it's the first I've read about mfg method related to barrel life.

I thought it was pretty common knowledge. It is, at least it is among competitive shooters.

Some features that make Cut Rifled barrels more durable than Button Rifled are that A)the grooves are usually deeper B) button rifled bores expand when you contour the barrel and C) It's easier to get a tapered bore with Cut Rifling.

Hammer forging toughens the steel, along with allowing deep grooves or grooves of nearly any design, including polygonal (such as on HK machinegun barrels). Hammer forged barrels can also be forged with a tapered bore which also enhances the accurate life. Hammer Forged bores shrink when you contour them too.

You won't find many serious competitors who will take a 3,000 or more round count button rifled barrel to Perry - it's too risky that the barrel will die in the middle of the National Championships. You will, however, see serious competitors take a cut rifled barrel to The Nationals with 4,000 rounds down range.

I thought everyone knew this, it's been researched pretty thoroughly by various military's. Unfortunately, I don't see these studies on-line, but here are a few links to get you started in your own research.
Armalon Barrels
Precision Shooting on HF
General Barrel Article
Bravo Co. HF Barrels

I simply don't have the background knowledge to comment.

I can comment from common sense though!

Groove diameter should not differ with process of making the barrel! IE. land diameter and groove diameter in a 6.5mm barrel should be .256" and .264" respectively no matter how it's made!

How can turning down the contour of a heavy barrel to a smaller diameter, lighter contour effect the INSIDE of the bore!?!?

quote:

Some features that make Cut Rifled barrels more durable than Button Rifled are that A)the grooves are usually deeper I can see that one can cut the grooves deeper and the extra metal exposed can serve to retard errosion!


B) button rifled bores expand when you contour the barrel and I'll take your word for it....but it does nothing for extending barrel life?...can you explain?


C) It's easier to get a tapered bore with Cut Rifling. Again....how does this extend barrel life?

Hammer forging toughens the steel, along with allowing deep grooves or grooves I can buy this easily

Hammer Forged bores shrink when you contour them too. If this is so.....how does this extend barrel life.....we just got done saying increased bores do the same thing?

You won't find many serious competitors who will take a 3,000 or more round count button rifled barrel to Perry - it's too risky that the barrel will die in the middle of the National Championships. You will, however, see serious competitors take a cut rifled barrel to The Nationals with 4,000 rounds down range.

I'm with butchlambert on this.....I just find this logic hard to swallow.....not that it makes any difference.....I'm still going to use button rifled barrels regardless of lifespan!

Button rifled barrels are great. They are cheap and capable of of match winning accuracy, no matter what your game. You shoot them for a season & toss them in the trash.

As for the rest of what you and Butch have said, you were asking me to speculate as to why what I said is true. I may or may not do a good job of that. I'm just a trigger puller. But I did supply you with some resources by some people who have some guesses that may or may not be better than mine. It really doesn't matter what you, I or they think are the causes of greater accurate life of cut vs. buttoned or hammered vs. cut. The reasons are mostly speculation. It is, and that's a fact.

I'm not here to argue with you, why don't you think about why hammer forged barrels last longer and come back and educate all of us?

Butch, of course you won't find cut or buttoned military barrels now - that went out before disco. They are all hammered now due to production rates and durability. Buttoning is nearly equal in production rate, but fails in durability.

quote:

Originally posted by BECoole:

Some features that make Cut Rifled barrels more durable than Button Rifled are that A)the grooves are usually deeper B) button rifled bores expand when you contour the barrel and C) It's easier to get a tapered bore with Cut Rifling.

and now you say

quote:

Originally posted by BECoole: you were asking me to speculate as to why what I said is true.

I sure don't look to me like you was speculating.

quote:

Originally posted by rolltop:
and now you say

quote:

Originally posted by BECoole: you were asking me to speculate as to why what I said is true.

I sure don't look to me like you was speculating.

Like I said, I gave you a good start on resources. Why don't you at least read those and get back to us? Then maybe you can criticize what I wrote with a little intelligence and not sound like someone who was stuck on a desert island since 1960.

Good articles BEcoole, I learned something

You seem to have a high opinion of hammer forged barrels?

My gunsmith has the opposite. While scoping my 7 RUM factoy Remington barrel which is really rough, his comment was "What do you expect for a barrel that was made in 6.7 seconds?!?!?"

The cut rifling on my Brux barrels explains why they are superb!

http://www.bruxbarrels.com/

quote:

Button rifled barrels are great. They are cheap and capable of of match winning accuracy, no matter what your game. You shoot them for a season & toss them in the trash.

Lothar Walther barrels are button rifled

They should be thrown in the trash before you waste your time and money installing them!

quote:

Lothar Walther barrels are button rifled

They should be thrown in the trash before you waste your time and money installing them!

I wouldn't consider that a condemnation of button rifling. A good deal of todays barrels are button rifled. Shilen and Douglas for starters.

There's a lot more to a barrel than the process of rifling.

BTW....I've never owned nor worked on a L-W barrel.

Not condemning the process, just LW!

The makers you mention are excellent!

quote:

Originally posted by rcamuglia:
Not condemning the process, just LW!

The makers you mention are excellent!

quote:

You seem to have a high opinion of hammer forged barrels?

I don't believe that they are benchrest quality (i.e. shoot in the zeros) but I do think there are some good ones out there (i.e. will shoot in the .2"s through .6"s), mostly the European ones. I'm going to try to get a Ruger blank. The main attraction of these is that I believe they will shoot good enough for NRA Highpower and do it (put 10 shots into 3/4 MOA) for more than one season (i.e. more than 5,000 rounds. I'll need closer to 10,000 round life for two seasons).

I've been shooting button rifled barrels and they shoot great (yes, even Walthers), better than I think a hammer forged barrel could do. I believe that a buttoned barrel will shoot with any barrel out there.

You won't get any argument from me about cut barrels shooting better than hammer forged either.

I'm either going to end up with a Ruger blank or I'm going to have a buttoned barrel nitrided. I get tired of swapping barrels every year.

I'd really love for someone to prove me wrong about hammered barrels by showing me a maker that consistently forges barrels that shoot in the zeros and ones. Or Hell, even in the twos.

Edited to add another interesting link for your pleasure. It even has the good professor's email address if you want to ask him any questions.
Prof. Higley's Homepage

BEcoole,
Sounds like you are more interested in a barrel that will last a long time rather than winning.
My experience with Melonite QPQ has been excellent. To get a decent price you need to get with a couple guys and do a group thing to get the good price.
Butch

For those of you that rate the depth of rifling by the method used are wrong. Contrary to popular belief button rifling can be had deeper then you would ever imagine.

All depends on how the button is made. SmokinJ is correct.
Butch

It's a 1 1/2 minute X-ring inside a 3 1/2 minute 10 ring. If the gun can shoot into half the X, there's no excuse for losing.

Hammer barrels aren't total dogs. Did you read Higley's article about .22 match barrels? It is not shabby and I'd like to see what could be done with a little more advanced barrel prepping.

http://technology.calumet.purd...merForgedBarrels.pdf

BECoole,
That is very old stuff. It shoots about as well as my 10-22. Go to the rimfire forum and search for Saaed's rimfire ammo test. It was done with a factory rifle. If they ever make a good HF barrel, I will buy one. They are just not competition barrels.
Butch

Why would someone buy a rifle/barrel based on how long it would last?? I seriously doubt that between the different mfging processes there is little difference in the overall longevity of the barrel. And relative accuracy is most often a subjective thing.
Seems like if you're shooting some sort of hyper-accuracy game, where shaving 1/16th" off your agg is reasons to celebrate, then how long a barrel lasts is of little concern to you. You just re-barrel each year and sell the old one to a varmint shooter. Seems like, if you seriously shoot matches, the cost of re-barreling should be just figured in. Like entry fees and travel money and front rest that cost over $1K and 4 figure scopes and buying a new action because it dumps the bullets out on the left instead of the right.
If you're a hunter, regardless of which barrel you have, you should get years and years of service out of your rifle if you take care of it.

quote:

Originally posted by wasbeeman:
Why would someone buy a rifle/barrel based on how long it would last?? I seriously doubt that between the different mfging processes there is little difference in the overall longevity of the barrel. And relative accuracy is most often a subjective thing.
Seems like if you're shooting some sort of hyper-accuracy game, where shaving 1/16th" off your agg is reasons to celebrate, then how long a barrel lasts is of little concern to you. You just re-barrel each year and sell the old one to a varmint shooter. Seems like, if you seriously shoot matches, the cost of re-barreling should be just figured in. Like entry fees and travel money and front rest that cost over $1K and 4 figure scopes and buying a new action because it dumps the bullets out on the left instead of the right.
If you're a hunter, regardless of which barrel you have, you should get years and years of service out of your rifle if you take care of it.

+1