quote:

Originally posted by craigster:


Rick,

It must really suck being you.

You are letting your dialog give you away here youngster! “Fuck Youâ€...â€Suckâ€??????????

Is there some gay thing going on here just underneath the surface?

Since you started this, why not raise the level a bit and enlighten everyone to these “highly skilled†machinist tricks that allow the thinning of a stressed barrel with absolutely no effect?

“Nothing is worse than ignorance in action“ craigster...so be careful with your answer!

I can't honestly say how many barrels I have contoured or recontoured. Certainly at least a couple hundred and probably more than that. No barrel from any well known maker has ever presented a problem and no factory barrel has ever presented a problem. Most have shot as well or better than before they were turned down. None shot bad. In those cases where the barrel shot significantly better, I attributed the improved performance to a better crowning job than the original.
Some barrels, usually from an obscure maker, were not properly stress relieved and warped to beat hell when turning them from the blank. These barrels would undoubtedly been just as much of a problem if I had been called upon to recontour them. A warping barrel is a warping barrel and, unless stress relieved, will continue to be so.
I have recontoured barrels from Remington, Winchester, Ruger, Douglas, Shilen, Hart, Smith, as well as numerous varied military barrels and have always had good results. I have recontoured both stainless and chromoly barrels.
In short, I don't consider it to be much of a problem and do consider it to be a task within the capabilities of any decent gunsmith. Regards, Bill.

Well Rick, I think Mr. Leeper answered your question regarding the skill level required to recontour a barrel. Hell, he considers it a task within the capabilties of any decent gunsmith. Being the self professed expert on anything and everything firearms related, it should be no problem, even for you! Anyway, thanks for your deep insight here on AR, it reminds me of the good old days when we had The Ass Clown with us on a regular basis. Nothin' like the original, but you're close enough. Keep up the good work and have a nice life.

quote:

Originally posted by Bill Leeper:
I can't honestly say how many barrels I have contoured or recontoured. Certainly at least a couple hundred and probably more than that. No barrel from any well known maker has ever presented a problem and no factory barrel has ever presented a problem. Most have shot as well or better than before they were turned down. None shot bad. In those cases where the barrel shot significantly better, I attributed the improved performance to a better crowning job than the original.
Some barrels, usually from an obscure maker, were not properly stress relieved and warped to beat hell when turning them from the blank. These barrels would undoubtedly been just as much of a problem if I had been called upon to recontour them. A warping barrel is a warping barrel and, unless stress relieved, will continue to be so.
I have recontoured barrels from Remington, Winchester, Ruger, Douglas, Shilen, Hart, Smith, as well as numerous varied military barrels and have always had good results. I have recontoured both stainless and chromoly barrels.
In short, I don't consider it to be much of a problem and do consider it to be a task within the capabilities of any decent gunsmith. Regards, Bill.

Bill, since you appear to be the only one here that has actually done this procedure (and many times) might I inquire as to what the reasonable charge to do this might be?

quote:

Originally posted by Bill Leeper:
Some barrels, usually from an obscure maker, were not properly stress relieved and warped to beat hell when turning them from the blank. These barrels would undoubtedly been just as much of a problem if I had been called upon to recontour them. A warping barrel is a warping barrel and, unless stress relieved, will continue to be so.

While I agree that the better quality barrels enjoy a greater number of successes, the fact still remains that removing material from a stressed barrel, and that's what we are talking about here, can create a problem. Having a stressed barrel warp is also within the capabilities of a "decent" gunsmith...

About 2/3 of the discussion here is somewhat edifying; the other 1/3 is not..............

Gentlemen,
(moderator's hat on) this is a discussion of turning a barrel, not one's bredding.. in lineage or preferences.

As you may note, frequently when a thread goes past 1 page, it degnerates into a feeding/name calling frenzy.

Of course I am guilty of the same thing.

Let's refrain from language that can not be broadcast on the radio, and "jokes" regarding illegal behavoir or injury to children. Things of this nature reflect poorly on the poster more than the "target" of the post. (moderator's hat off)

Now, on barrel turning and recontouring.. sure, it can be done.. it's probably less stressful on the barrel than a rebore. It PROBABLY will require some degree of straightening, then again, any bored barrel that is shaped will probably reuire the same.. either during the machining process being very careful on HEAT and accuracy or cleanup after the fact. We've all had barrels that weren't concentric bore to contour..

Douglas, Shilen, Pacnor,Bauska Shaw.. ALL bore and rifle the blank then contour. I've been to shilen's shop and watched it happen. It is simply too easy to fixture a consistent blank than a contoured one..

I understand that some cut rifles are bored, contured, then finish bored and cut...

Rem, Win, Ruger, Savage.. all are rifled then contoured.. Ruger, with it's hammer forged barreld HAVE to be.


One way to make certain it walks ..Should a ham handed shoprat take too deep cuts, not watching the heat of the barrel, and not being really careful of initial layout, it will almost certainly be ruined....

Should someone take good care, light cuts, and coolant, your chances of success go far higher

jeffe

Malm

Okay, I admit, I am not a steel chemist or engineer, and although I know a little bit about machining, its not about barrel shaping.


So here is my question.

If, as Jeffe said, you take a length of steel and you drill a hole in it and you then rifle it and you then you take metal off of it so as to make it into the shape of a barrel that somebody would want to use to put on a rifle, aren't you constantly putting stress on it by doing all of that shaping to get it to the point of somebody wanting to put it on a rifle.
Or, in other words, when one orders a shaped #2 Douglas blank, hasn't that thing had a lot of stress put into it already, and is sitting there with a lot of stress in it. So, if one buys that blank that has all of that stress in it from shaping at the factory and shapes it a little bit more, e.g. a continuation of shaping, how does that hurt the barrel?

quote:

how does that hurt the barrel?

PM sent

I would suspect a lot of barrels that shot worse after turning were indicated on the OD during set-up, not the bore. A lot of mass-produced barrels are turned off-center and when you thin the wall, you exacerbate the problem. In that case, a properly re-contoured barrel can correct a problem instead of cause one.

Brockman had to recontour a bunch of the first 550 Magnum barrels for just that reason.

quote:

Originally posted by tiggertate:
I would suspect a lot of barrels that shot worse after turning were indicated on the OD during set-up, not the bore. A lot of mass-produced barrels are turned off-center and when you thin the wall, you exacerbate the problem. In that case, a properly re-contoured barrel can correct a problem instead of cause one.

Brockman had to recontour a bunch of the first 550 Magnum barrels for just that reason.

Gee, and here I thought everybody used a piloted center drill on both ends first, and then installed on centers to take a light cut so that the thing is absolutely perfectly round.

Money talks and Bull Shit walks. Alot of the latter here.

Skill is obviously a factor, tough pill to swallow I know, and so far people are guessing.

Hot Core, I've had two barrels turned down by Bill Leeper. One of them twice. Shot another one the other day. How many have you had turned?

Malm, Rick, Jeff, how about you guys?

Chuck

Does recontouring require working up new loads, due to the obvious change to barrel harmonics?

quote:

Money talks and Bull Shit walks

Ain't that the truth!!!!!

I had a load worked up for a rifle that Bill turned down and absolutely nothing changed. Accuracy, velocity, nothing.

Chuck

Maybe Chuck and I are just lucky, but I also have had two barrels turned down by Bill Leeper. Both Pac-Nors.

The first was a #3'ish contour in 6.5-06 that post treatment would AVERAGE about 3/10" at 100 yards for 3-shot groups with 125 NPs. Way under an inch at 200 yards. I shit you not.

The second was a #5 358 Norma that he turned way down, took about 11oz off as I recall. He built the original rifle to my specs, and it was a muzzle heavy, graceless pig with terrible balance. After he turned down the barrel, the rifle turned into a racehorse, and shot just as well as before turning. In the 6/10" range with 250 North Forks.

quote:

Gee, and here I thought everybody used a piloted center drill on both ends first, and then installed on centers to take a light cut so that the thing is absolutely perfectly round.

That's where thinking got you, (thats a fun poke not a jab )
In industry we use barrel plugs sets that are made in .0005" diameter increments about 4-5 calibers long that slip into the bore, they have a head on them with a large center hole in them so that the machines can get an excellant purchase on the plug that would otherwise ruin a barrel.
The plugs provide about 30% greater ability to hold runout tolerance than simply locatiing on a center cut in the barrel's bore.

Here’s a great article on the making of barrels that appeared in Precision Shooting Magazine in 1995.

Read page 7 on “Profiling†to get an understanding of stresses induced by the manufacturing process.

The info that Hot Core posted earlier is probably the best and most reliable way to have a used barrel re-contoured in order to minimise the risk of metal moving on you.

Of course you have to have machining skill in order to contour a barrel (no one said you didn’t), but that skill does not help you at all in regards to any stress that is released by thinning the barrel walls. The thinner steel cannot resist the stress the same as the thicker steel did, and how, or how well, it was made thinner is irrelevant.

I’ve never had a barrel re-contoured because I have never found it necessary to do so. I design and plan my rifles BEFORE I buy the parts, not afterwards.

http://www.border-barrels.com/articles/bmart.htm

Jezuz H,

What a bunch of crybabies here. Look, some of what Bill Leeper, Rick, and Malm said is right. They are all right to some extent.

The common thread here seems to be that the recontouring of "good" barrels is relatively risk free. It is not however guaranteed. Lesser quality barrels are a real crap shoot. the problem is, identifying the "good" one. It's a gamble. And not everyone likes to gamble.

One thing I have noted is that many times stress is induced during the contouring process when the barrel is held between centers too tightly. As the barrel heats up it expands. If the tailstock is not constantly adjusted to account for this growth the bearrel will bind. I've seen the barrels expand enough to lock up the lathe. That will certainly induce stress into a barrel no matter who made it. This is a good use of a spring loaded center.

I have seen lots of barrels recontoured with no noted ill affects. However, I have seen some that did not fare so well through the process. Again, it is a gamble. Sure, using a good barrel improves the odds but nothing is 100%.

I find it funny that you folks who are not capable yourself attack those who are in the business for making a sound business decission. If Rick and Malm decide they do not want to tackle the task of recontouring a barrel you immediately challenge their qualifications. Seems to me that all businesses make strategic decisions and risk evaluations before accepting jobs. Based on their experiences they choose not to subject themselves to the aggravation. You attack them, I applaud them. Too many would be smiths out there accept jobs they have no business doing and the customer suffers. Others I believe inflate their success rate.

quote:

Originally posted by Rick 0311:
I design and plan my rifles BEFORE I buy the parts, not afterwards.

Very sound advice. Far too often when someone commissions a smith they do not seek the advice of the smith beforehand. All too often they assemble a hodge podge of parts and ask to have them assembled. Never once does it occur to them to discuss beforehand things like balance, weight, profile, etc. The result is after the fact changes like those being discussed here.

There is a big difference between inducing new stress into a barrel by sloppy machining and releasing stress that is already present in the steel due to manufacturing and/or being fired. The first can be avoided by a skillful smith, the second is a total crap shoot since you have no way to predict the placement or the amount of stress present in the steel.

The removal of the steel can be accomplished as skillfully as possible but the finished thickness may also be totally incapable of resisting the force being released against it, and you won’t know that until it is too late.

Now, maybe you will get real lucky and have the metal move in a direction that actually improves what was there to start with...but to me that’s a pretty silly way to build a rifle since it is a total gamble without very good odds in your favor.

quote:

Originally posted by Chuck Nelson:
Money talks and Bull Shit walks. Alot of the latter here.

Skill is obviously a factor, tough pill to swallow I know, and so far people are guessing.

Hot Core, I've had two barrels turned down by Bill Leeper. One of them twice. Shot another one the other day. How many have you had turned?

Malm, Rick, Jeff, how about you guys?

Chuck

Chuck, I can't tell you how many barrels I've turned over the years. More than one, less than 200 maybe, and while skill is certainly a key factor, the individual barrel has to be a willing partner. And while it is true that the better quality barrels experience a higher success rate, it doesn't mean they all do. Because no matter how careful barrel manufacturers are, shit slips through. Surely some of these make it North.

quote:

Originally posted by Bill Leeper:
I can't honestly say how many barrels I have contoured or recontoured. Certainly at least a couple hundred and probably more than that. No barrel from any well known maker has ever presented a problem and no factory barrel has ever presented a problem. Most have shot as well or better than before they were turned down. None shot bad.


I have recontoured barrels from Remington, Winchester, Ruger, Douglas, Shilen, Hart, Smith, as well as numerous varied military barrels and have always had good results. I have recontoured both stainless and chromoly barrels.
In short, I don't consider it to be much of a problem and do consider it to be a task within the capabilities of any decent gunsmith. Regards, Bill.

quote:

Originally posted my Malm
Chuck, I can't tell you how many barrels I've turned over the years. More than one, less than 200 maybe, and while skill is certainly a key factor, the individual barrel has to be a willing partner. And while it is true that the better quality barrels experience a higher success rate, it doesn't mean they all do. Because no matter how careful barrel manufacturers are, shit slips through. Surely some of these make it North.

Does anyone see a difference here?.....

Okay folks, what about this.

What about a guy like, say for example, Mark Stratton, who takes a contoured barrel and in essence recontours it by machining the hell out of it until its octagon? Surely that has to add as much or more stress than a continuation of the profiling process, or not?


Poleax

You stated you have seen a lot of barrels that fared well after recontouring, and some that didn't. Tell us more about them. What brands of barrel were they. Who recontoured them. What did the so called "good" ones shoot before and after recontouring. How about the so called "bad" ones?

When someone says “most†have shot as well or better...is it reasonable to assume that “some†of them shot worse than before? If so, what caused that? Was less skill used in the re-contouring of those that shot worse?

It would also be instructive to know how many of these were new barrels and how many were used barrels, since that information wasn’t provided and that was the basis for the original question posed on this thread.

quote:

Originally posted by 22WRF:
Poleax

You stated you have seen a lot of barrels that fared well after recontouring, and some that didn't. Tell us more about them. What brands of barrel were they. Who recontoured them. What did the so called "good" ones shoot before and after recontouring. How about the so called "bad" ones?

I consider any barrel that provided acceptible hunting accuracy after recontouring to have fared well. For me that is any rifle that will shoot about 1" or better. Now, I further consider it mandatory that these same "good" barrels not display a tendency to wander as things heat up. Do normal hunting barrels get shot that much, no, but if you fire several 5 shot strings and the average POI does not wander around like a drunk then I consider that a success. You are asking if I have recorded somewhere the average group size before and after recontouring. No. Who the hell keeps those kinds of records or has time to? It would be impractical. About all one has to rely on is what the owner says they shot like before bringing one into the shop. I have not personally had a recontour job perform noticably worse than before. I know that I am lucky though and I'm sure much of that is due to the relatively small sample size. I have seen friends, students, and acquaintances bang their heads against the wall though due to barrels which perfomed poorly afterward. Many of these I attribute to the aforementioned failure to properly account for heat expansion. But many must have been related to either release of or inducement of stress into or out of the barrel.

I think for the purposes of this discussion Mr Leeper's list of "good" barrels and mine could be considered the same.

Separating the wheat from the chaff (so to speak) it appears from this lively discussion that recontouring will probably (but not postively) be successful so long as one is careful doing it.

another small sample size (but they add up), I've had a Brno 602 barrel with 100-200 rounds through it turned by Bill and it shoots extremely well, better than before, though I attribute that to the fact that it was fitted to an action that Bill also trued up, rather than to the fact that it was turned.

I've also used or given away six heavy 308 barrels off my high-power match rifles, which were turned to sporter (one featherweight) contours and fitted to hunting rifles. these all had 2000+ rounds through them and all made wonderfully accurate hunting rifles. these were Kreigers or Rock 5R's, and were all rechambered to 30-06 or 300 mags, with as much of the old throat removed as possible.

As far as the original question, I would not hesitate to have a newly installed barrel re-contoured.

22WRF, I see your point in turning between centers, but you do not really think that the barrel is streight enough to turn it that way and have the bore centered for the entire length of the barrel.

By the way, for all those who have a hankerin to do some barrel contouring, Mark Stratton has a great little article along with plans for a tool to do it in his book. If you look at page 109 he talks about a Lathe Radius Contouring Fixture that looks like it would be just the ticket for what needs to be done.

quote:

Originally posted by 22WRF:
By the way, for all those who have a hankerin to do some barrel contouring, Mark Stratton has a great little article along with plans for a tool to do it in his book. If you look at page 109 he talks about a Lathe Radius Contouring Fixture that looks like it would be just the ticket for what needs to be done.

Ask Mark sometime what “can†happen when contouring a barrel that has any stress in it.

Mark

What can happen when contouring a barrel than has any stress in it?

quote:

Originally posted by 22WRF:
Mark

What can happen when contouring a barrel than has any stress in it?

See, you do have a good sense of humor when you want to!!

I will try to do a little explaining here and hope my limited communication skills are up to the task. Keep in mind, this is all based on my experiences as a gunsmith and in general machining.
When a barrel is turned, as with any stock removal operation, stress is not induced, only removed. An exception MIGHT be when a dull tool is used which tends to displace material rather than cutting it.
Stresses are existent in most pieces of steel straight from the mill to a greater or lesser extent depending on the final form of the steel and the technique use to achieve this form. So, you may have a piece of steel which is a perfect cylinder but which is such because internal stresses counter each other perfectly at it's present size and shape. As material is removed, some stresses are removed with it. This leaves behind the residual stresses which, with no counteracting force, are free to affect the shape of the piece so it warps. This is, perhaps, a bit simplistic but is the best I can do to explain the warping of a piece of steel when it is machined.
Most barrel makers start out with a piece of steel which has been stress relieved. That is, it has been heat treated to make it as inert as possible while still being within the desired hardness specifications. If the method of manufacture is such the stock is only removed ( as in rifling which is cut or broached) there will be no stress induced and the resultant blank will probably be as inert as the raw blank was. If the method of manufacture displaces material to achieve the desired form (as in button rifling) then stresses will certainly be induced and re-treating of the blank will be necessary prior to profiling. If this is properly done, the blank will be relatively stress free and turning will be trouble free. If the button rifled blank is not stress relived, the barrel will warp and the bore expand when the barrel is turned. To make matters worse, bore expansion might not be uniform so that the bore may grow and distort at the same time. Not a pretty picture. I have purchased barrels which had this problem and they were practically unusable. When I run into this from a given maker, I simply never again buy barrels from that source and the problem is solved!
If the stress relieving has been properly done though, such a barrel will turn beautifully and the results will be good.
I have had situations where it was immediately apparent that the barrel was not stress relieved. It started to warp with the first cut. All was not lost however. It was possible to straighten the barrel, stress relieve, then finish the job.
Probably the most common myth regarding barrel contouring is the "light cuts" myth. This one tells us that the workman must take only the lightest of cuts and never let the barrel get hot. Sounds good but it just isn't reasonable machine shop practice. In reality, one takes as heavy a cut as the setup, machine rigidity, etc., will allow. I will usually take cuts of about .050" (.100" diameter reduction) from a full blank. As the barrel diameter is reduced, the depth of cut is also reduced as the slimmer barrel is not rigid enough to support the heavier cut. A barrel which is finishing up at around the same contour as a winchester featherweight, for instance, will see a final cut depth of perhaps only .025".
When turning barrels, I find warpage to be less a problem than chatter and chattering is what usually has the greatest influence on cut depth. FWIW, when I turn down a blank, it is hot enough when finished to cause water to sizzle unless I'm running with coolant. I prefer to use coolant because tool wear is better but I don't think there is any real difference in the finished product.
Someone asked what a normal cost might be. I would guess that this might reasonably be expected to range from 120.00 up to double that. I try to never quote my own prices over the 'net. Since I'm not looking to increase my customer base it's a moot point anyway!
There is a lot more I could say but I'm tired now! Regards, Bill.

Since I have experienced much of the same, I will spare everyone my detailed procedures as to how I contour barrels.

Regarding quality barrels, most of our top barrel makers acknowledge that bore dimensions are prone to change when reworking their barrels. Here are a couple of examples which are posted on the companies web sites.

From the Hart Rifle Barrel Company web site:

quote:

Why does Hart Rifle Barrels prefer to contour your barrel blank?

We prefer to contour your barrel to your contour specifications, plus a few thousands to allow for polishing the barrel. The barrel is final lapped after it is contoured to meet our guaranteed tolerance. Contouring a barrel after the hand lapping will cause the barrel to fall outside of our specifications, as when you contour a blank the interior dimension will increase.

And that's with a new, stress relieved blank. Wonder what "could" happen to a barrel that has seen some use?

From Shilens web site:

quote:

What about "fluting" a barrel?
Fluting is a service we neither offer nor recommend. If you have a Shilen barrel fluted, the warranty is void. Fluting a barrel can induce unrecoverable stresses that will encourage warping when heated and can also swell the bore dimensions, causing loose spots in the bore

Although this one pertains to fluting, it still applies as you are working the material around the bore.

Long story short, shit happens. Pay your money and take your chances.

Malm,
I always kind of thought that Hart (and others) should have said dimensions "may change" rather than "will change". I had this discussion with a couple of makers nearly 30 years ago and asked how much a blank changed when turned from full diameter to LV contour. Both said they had not ever checked but it stood to reason that such a change would take place. Regardless, my best performing BR barrels were barrels I had tapered myself.
Fluting is a whole different matter. It is not too unlikely that the cutter used for fluting may dull during the course of the job and start displacing material rather than removing it. This does induce stresses into the barrel. The same can be true when milling octagonal barrels.
I would never flute a barrel on one of my match rifles. Regards, Bill.

Bill,

I know that I was careful to say that things “may†change...but a bunch of people posting here gave the impression that NOTHING would change if the person doing the work was “highly skilled.â€

That, to me, was just a bit misleading to a person contemplating having this done to his barrel.

A guys gonna do what he wants...but I think it is best to give him all the pluses and minuses and let him make an informed decision based on that.

My experience has been that nothing is certain. I try to always use terms like: may, can, could, perhaps etc., because nothing is set in stone when it comes to rifles and accuracy. I've seen too much shit happen to make claims to the contrary. I too would never flute the barrel of a match rifle.

I wonder why David Miller flutes the barrels of his Marksman Rifles? And again, I wonder what happens to Mark Stratton's barrels when he machines them octagon?

Krieger will flute their new barrels for you, but their’s are cut rifled which doesn’t induce stress like button rifling does. I doubt, however, that Krieger would agree to flute one of their barrels after it had been fired.

I’m sure Mark will correct me if I’m wrong, but I don’t believe that he does his octagon jobs on used barrels...only on new, high quality ones that have been stress relieved by the maker.