Barrel fluting


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rlpinca
December 25, 2002, 09:20 PM
Is barrel fluting a good idea for the extra money that is involved? I'm asking in specific for an AR15 that will occasionally see some rapid fire.

What I know so far is that it increases surface are in order to provide faster cooling. It also decreases weight a little bit.

I've also heard that it stiffens the barrel quite a bit and helps out in the accuracy department. The critics claim that the fluting process induces alot of stress into the barrel and can actually harm accuracy. They also claim that the increased cooling and the weight savings don't justify the extra money and possible extra stress.

I'm just wondering if it's worth the extra money or if I'd be better off spending that elsewhere.

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Wildalaska
December 25, 2002, 09:28 PM
The only downside to fluting is the stress it causes to the barrel. What we do after fluting is simply have the barrel cryo'ed..that releives the stress..

Fluting is excellent for AR15 barrels and M16s,,,

George Stringer
December 26, 2002, 09:06 AM
As Wildalaska said it can introduce stress into the barrel but I've done several that showed no signs of it. It is still a good idea to have them cryoed after fluting. Fluting doesn't make a barrel stiffer. But a fluted barrel will be stiffer than an unfluted barrel of the same weight because you started with a heavier barrel. George

rlpinca
December 26, 2002, 04:15 PM
Thanks guys. I was just wondering about that. I'm looking around for an ar15 and have been seeing mixed opinions on it.

Art Eatman
December 29, 2002, 02:19 PM
You can go back to TFL and look under "The Wisdom of Gale McMillan". The caveat is that I don't know if cryogenic treatment was in vogue when he made his comments.

Art

larryw
December 30, 2002, 06:51 PM
For cryo treatments, http://www.cryoplus.com/ is highly recommended. Good prices, fast turnaround.

mete
December 31, 2002, 08:50 PM
As a metallurgist I am amazed that so many have been duped by the cryogenic myth. In all my years as a metallurgist if we wanted to stress relieve metal we HEATED it. Some of the barrel makers such as Shilen will tell you the facts but others such as Krieger will gladly take your money. Any machining can introduce stresses though if care is taken those stresses wiil be minimal. I'll be happy to answer any questions about cryogenics.

Badger Arms
January 1, 2003, 06:27 PM
Try Kurts Custom Firearms (http://www.kurtskustomfirearms.citymax.com/page/page/8932.htm). They seem to have good prices and the guy seems straight-up. Here's the link if you can't get it by clicking above

http://www.kurtskustomfirearms.citymax.com/page/page/8932.htm

jrhines
January 1, 2003, 10:49 PM
I would be interested in your views on the cryo treatment . I am a machinist and do a bit of smithing, including heat treating. All of mine is done in a muffin furnance, none in anything cooler than my quinch tank.

This might be a topic of a new, intresting thread.

J Rhines
Seneca, MD

Wildalaska
January 1, 2003, 11:25 PM
Mete, Id like to hear your views on cryo also...

Nero Steptoe
January 2, 2003, 01:29 PM
Mete, I'd love to hear the depth of your experience in cryogenic stress relief in metals. What kind of equipment did you use?? What metals did you employ in your experimentation??

Are you aware of work done by other metallurgists in the field of cryogenic stress relief?? What were their findings?

mete
January 2, 2003, 04:15 PM
Nero, my experience in stress relieving is years of doing it by HEATING. In any case lets take the statements of Cryoplus with my comments. 1-cryo will anneal the metal = annealing by definition is heating ( even my 1935 Funk &Wagnalls says that) 2-forms denser molecular structure = this is a pet peave of mine, metals do not have molecules nor do they have molecular bonding this is something you find in plastics. Metals have metallic bonding. 3- forms microfine carbides = this I think they took from a study about TOOL STEEL.The typical chrome moly barrel (such as 4140 ) is not tool steel and acts differently. Other comments that you might see about retained austenite also pertain to tool steels . All my comments require that you can deal with reason, logic and scientific fact.

Badger Arms
January 2, 2003, 09:23 PM
Metals do have molecules and they have grains as well. The granular structure of the metal dictates much of what we know as the properties of hardness, brittleness, tensile strength, etc. Many of the alloying agents in metals are there to change the nature of the granular structure. Cryogenic treatment does something, but many argue over what exactly it does. One thing is for sure, it does stress-relieve metal. It also, from what I've experienced, makes tools last longer. This is particulary true of band saw blades. The same should also apply to barrels, but I'm not sure if many users would experience any advantage from this over any other procedure (fire-lapping, 'break-in' procedures, recrowning, etc.).

My personal opinion, if you have the money and it makes you feel better, it won't hurt and will probably help. Don't expect miracles.

BTW, Mete, it doesn't form a denser molecular structure, but it does relieve intergranular stress.

mete
January 2, 2003, 10:08 PM
Badger, please do some research in basic chemistry and learn about the different types of bonding, If you do you will find that metals do not have molecules.The type of bonding gives metals their properties as apposed to those of plastics. The basic reason for cryogenic treatment is to reduce the amount of retained austenite in the steel. This is a factor only in steels of fairly high carbon ( ~ 1% ) and significant amounts of other alloying elements, that is tool steels. That would include band saw blades. In practical experience it helps in some cases but not others, you have to try it. And in some cases such as case hardened bearing some retained austenite is beneficial. As far as stresses, residual stresses distort the crystal structure. This can be measured by X-rays. Atomic activity is higher at higher temperature and since you want those atoms to move , stress relieving is done by heating. This you can find in metallurgical texts, heat treating books. specifications etc.

Badger Arms
January 3, 2003, 12:35 AM
Austenite is ferric carbide (a molecule within metals) which is an impurity among dozens of common impurities (molecules) within iron compounds such as steel, stainless steel, carbide steel, etc. Impurity might not be the best of terms because it does add certain benefitial properties to the steel. I'm not sure if I remember correctly from college, but I think that this is a stainless steel compound. Anybody? It seems you might be misunderstanding the use of terms here. Molecules are groups of atoms bound with electromagnetic forces. Some of these forces are quite strong such as the bond between Hydrogen and Oxygen within a water molecule. Others are comparatively weak such as the bond between two iron atoms in the molecular structure of steel.

I doubt very seriously if cryogenic treatment does anything for the levels of any carbon compound in the steel. It is my understanding that cryogenic treatment merely reduces the volume of the steel significantly enough to rearrange the grains within the steel in a more uniform manner. When steel is formed, forged, cast, etc., it slowly cools. Irregularities in the cooling level within adjoining grains creates stresses in these areas. These stresses are relieved somewhat by further cooling the grain structure and squeezing these grains into a more uniform and less internally stressed structure. This is a factor in all steels, not just high-carbon steels.

Finally, I've not seen any evidence that this is significant enough to warrant spending the money on it, but the process does accomplish something. Arguing about the semantics won't help us. That said, I'm not really sure I understand what you mean by a 'molecular bond' and what significance that has to metalurgy. It seems that you are refering more to an adhesive term.

mete
January 3, 2003, 01:32 AM
Badger, I am not misunderstanding terms and I don't want to argue ,only educate. Austenite is not ferric carbide, it is a face centered cubic crystal structure found in iron and iron alloys. Groups of crystals (not molecules) form grains. Impurities are unwanted elements in steel, desired ones are alloying elements. Austenite is the structure of austenitic stainless steel ( 300 series) The difference in types of bonding is very significant, for example metallic bonding gives you electrical conductivity in metals. Stress relief HEAT treatment is normally done between 900-1250 F this permits atoms to move and relieve stresses.

George Stringer
January 3, 2003, 08:32 AM
I'm not a metalurgist and I don't know from atomic molecules. But it sounds like you are both right and just using different terms to express it. Tempering hardened steel is done by heat. Stress relief is simply tempering in that light. On the other hand Cryo does do something. Cryo, I think you are both saying, is a shot in the dark. From my experience with it that is absolutely correct. I may have sent several barrels to be treated for customers. Out of those I'd say 2/3 of them reported improvement and the rest except for one saw no change in accuracy. The one guy said his groups actually got bigger after treatment.

I think this could be a very interesting discussion. You might cite some references for those interested to look up. The following is a quote from One Cryo www.onecryo.com

"A One-Time Permanent Process Which is Not a Coating and Will Not Wear Off. Cryo Stabilizing Increases Dimensional Stability, and Accuracy of your gun barrel 15 to 30%. Reduces Wear, Friction, Heat and Warping, Resulting In Consistently Tighter Shot Groups. Cryo Stabilizing Closes and Refines Grain Structure of Ferrous Metals, Stress Relieves Aluminum and Other Non-Ferrous Alloys For Tighter Tolerance Machining"

Make sense? George

mete
January 3, 2003, 11:44 AM
No George. Their website has a good bit of misinformation like the others. Least you think that stresses in barrels is something new , there is an excellent discussion of the subject in " The Modern Gunsmith " by Howe, 1941 edition, Supplement page 21. Maybe we should leave it there, if $50 makes you happy it's cheaper than going to a shrink.

Wildalaska
January 3, 2003, 02:17 PM
We have had nothing with sucess from cryo..I dont pretend to know how it works...but it does....

JollyWhiteGiant
January 3, 2003, 02:47 PM
If you are planning on fluting a standard or HBAR conture barrel, save yoru money as it woun't reduce weight enough to really notice. If you are getting a bull barreled rifle it can save you quite a bit of weight depending on who does it and how deep they go with it.

It may help cool bull barrels quicker but doesn't do much for HBAR barrels.

Any shop that does fluting should releive their barrels after doing it. I too would stay away from Cryo, and only use it as a last resort if you can't get it to shoot and even if you get increased accuracy it will not be dramatic.

Frohickey
January 3, 2003, 03:24 PM
Please. Keep the metallurgy class/discussion going. Thats one of my interests, though I admit, I'm very much a layman at it, but its one of those things that I took a class in college, and have been fascinated with since.

It might be, as far as cryo-ing and heat treating for stress relief, is that its the uniform cooling that is what is required. With heating, don't you lose some desired structures depending on how long it was heated?

And for fluting and cooling of the barrel, sure, you increase the cooling effect, because you have just increased the surface area of the barrel. But a lighter barrel has less metal and tends to heat up faster than a heavier barrel. I think that its a wash as far as number of shots fired from a cold barrel to temperature.

Nero Steptoe
January 3, 2003, 04:48 PM
Mete: I have a college-age son...just wondering where you got your degree in metallurgy?? Your assertion that metal "doesn't have molecules" is the most bizarre statement I've heard from somebody professing to be a metallurgist. In other words, iron isn't made up of atoms that form molecules??

Maybe I'm missing something here, but I'd hope that many complaints would have been filed with the Federal Trade Commission if the several companies that offer cryo treatment of metals just happen to all be frauds.

As I said, have you done any research into work done by any PUBLISHED metallurgists regarding their work in cryo stress relief in metals??

Delmar
January 3, 2003, 05:37 PM
Well, so far as it goes-if you want to increase the surface of the barrel in order to affect cooling, glass beading the exterior is going to give you more surface than fluting.

mete
January 3, 2003, 05:54 PM
Nero, Polytechnic Institute of Brooklyn ( now Polytechnic University). I'll try it again. In metals groups of atoms form crystals not molecules. This is bizare only if you don't know science. Austenite -face centered cubic crystal, ferrite- body centered cubic crystal, martensite- tetragonal, these are the three CRYSTAL structures ( NOT MOLECULES) that we deal with in iron alloys. If you can't even get to square #1 I can't help you.

romulus
January 3, 2003, 07:03 PM
No offense, but I find the statement bizarre also...Mete, does it hold true only for metals that crystals have no molecular structure? Diamonds and other crystalline gems have a molecular structure. What is it about metals, that the atoms would somehow refuse to bond and form molecules?

Also, as I understand it the definition of "annealing" is the softening of metal...does it have to be done by heating? If cryo-handling of steel results in a softer metal, why is it not annealing? Could you kindly refer me to a text other than Funk and Wagnall that might shed light on the subject?

Just curious...

mete
January 3, 2003, 08:52 PM
Metallic bonding - large interatomic forces are created by the sharing of electrons in a delocalized manner to form strong nondirectional bonding. Its not a matter of refusing to form molecules its just that they are metals and are doing their metallic thing. According to the American Welding Society...Stress relief heat treatment is the uniform heating of a structure to a suitable temperature below the critical range of the base metal...Annealing or full annealing consists of heating the part 50-100 F above the critical temperature ( where ferrite changes to austenite) and cooled slowly. Can't help you about the gems, not my department.

Nero Steptoe
January 3, 2003, 09:35 PM
mete: Thanks for your patience. The terminology that you're using sounds more like that of a welder than of a guy with a post-secondary degree in chemistry, etc. Granted, that could just be my ignorance of the metallurgy terminology.

So, what about my questions regarding your knowledge of metallurgists who have done research and published on cryo stress relief?? Does such research exit?? Do any reputable metallurgists disagree with your opinions regarding cryo?

And, also, are all the businesses that offer cryo stress relief just scams and frauds?? If so, why don't we hear about folks going to jail, being sued, etc.???

Inquiring minds want to know! I remain eagerly anticipating your further edification.

romulus
January 3, 2003, 09:55 PM
Can't help you about the gems, not my department.

The chemical and physical laws that apply to gems apply to all of earth's elements. Molecules are composed of atoms joined together by some sort of chemical bond, be it covalent, ionic, whatever. I fail to see how crystals of a particular metal are non-molecular, when all substance in this universe is either atomic or molecular, the latter being the preponderant case, as pure elements are rare indeed. Just my recollection of basic chemistry, that's all.

As far as metallurgy is concerned, is iron oxide not a compound and hence identifiable by a discrete molecular arrangement? Aluminum oxide? Copper sulfate?

Again no offense intended, but if your statements on the physical-chemical nature of steels are suspect, it follows that so are the ones you make on cryo stress relief...

mete
January 4, 2003, 02:51 AM
How about logic ; for stress to be relieved atoms have to move, the lower the temperature the less able they are to move. But I've said enough on this subject. By the way since George finds that cryo works 2/3 of the time you might ask him to explain why it doesn't work 1/3 of the time. This subject is now closed.

Nero Steptoe
January 4, 2003, 10:32 AM
"How about logic ; for stress to be relieved atoms have to move, the lower the temperature the less able they are to move. But I've said enough on this subject. By the way since George finds that cryo works 2/3 of the time you might ask him to explain why it doesn't work 1/3 of the time. This subject is now closed."

Not meaning to flame, but the above response is very much like the response the Raelians gave regarding their claim to have cloned a human. Appears to this layman that a certain "metallurgist" might just be a welder who has little understanding of atomic structure or cryo research.

Badger Arms
January 4, 2003, 12:17 PM
for stress to be relieved atoms have to move, the lower the temperature the less able they are to move.

But this is not true, Cryogenics does not just merely start and end with a supercooled product. Much like heat-treating, you start with a room temperature product and variably heat and, in this case, cool it at certain levels for certain time periods to get the desired result.

As for logic, laymans terms can compare it to cold-rolling. This is a process whereby aluminum (what I know it from) is pressed between rollers to compress the grain structure. This is done at room temperature and, doesn't it make logical sense, the compressing is done mechanically. Why can't this stress be applied with supercold temperatures. When you cool metal, or anything for that matter, it compresses within itself. Do this with glass and it often cracks. Do this with metal and the granular structure is compressed also. When reheated to room temperature, the stresses are relieved.

And my third point, why does it only work 2/3rds of the time? Well, modern alloys have not been engineered to be cryo-treated. Without knowing the heat-treatable properties of a metal, if you were to heat and quench steels at random you could probably get a desireable quality out of them 2/3rds of a time.

I'll second the call for a peer-reviewed article on the matter. Anybody know of one in a scholarly journal? Shouldn't be too hard to find.

Sean Smith
January 12, 2003, 08:13 PM
mete is right about metallic crystals, and everyone else is 100% dead WRONG. Should have stayed awake in science class, folks. A metallic crystal lattice (e.g. a hunk of steel) has NO molecules, and NO atoms in its structure, either (unless you count trace random impurities, which of course could be made of ANYTHING). If you think otherwise, you just have no clue what you are talking about.

That's right, if you made a 100% pure bar of iron metal (or any other metallic element) it would have NO molecules and NO atoms in its structure.

I say again, there would be NO discrete "molecules" whatsoever in its structure. There are NO "complete" (i.e. electrons, protons & neutrons in one unit) atoms at all, just the positively-charged nuclei (ions) of metallic elements, and delocalized electrons. Alloys/impure metals can have different things added to the crystal lattice, of course, and can form different sorts of crystal structures, but there is no such thing as "a molecule of alloy X."

By the way, lots of compounds don't have molecules in them at all, not just metallic crystals. Sodium chloride and other ionic solids don't have molecules or atoms, either... they are all crystals composed of repeating patterns of ions. People confuse ionic compounds with covalent molecules, but ionic compounds don't have molecules in their structure in any real sense... they are just a repeating pattern of ions.

http://www.wpbschoolhouse.btinternet.co.uk/page04/4_72bond.htm

I can't speak to how well the cryogenic stress relief bit works, though.

As far as metallurgy is concerned, is iron oxide not a compound and hence identifiable by a discrete molecular arrangement? Aluminum oxide? Copper sulfate?

You are obviously confused. Lots of covalent molecules and ionic compounds can be formed with metallic elements. Those compounds do not form metallic crystal lattices ("metals" in the layman's sense of a bar of iron) and so are irrelevant to the discussion at hand... kind of like comparing the properties of table salt to chlorine gas because sodium chloride contains chlorine ions. In other words, just about utterly irrelevant.

Badger Arms
January 12, 2003, 09:02 PM
Hate to do this, but.... Sodium Chloride is a MOLECULE by definition. It is made up of two ATOMS, one Sodium atom and one Chlorine atom. Any structure made up of same will be made up of atoms and molecules forming a crystaline structure. I was awake for that part of the class.

As I and others have stated in this and another thread, none of this matters much. Cryogenic stress relief DOES do something some of the time and nothing some of the time. Therefore, if SOMETHING is happening and it gets figured out, a benefit could come from the process. It took them a while to figure out heat treating, cold working, hammer forging, quenching, dwell times, alloying agents, stress relief, case hardening, etc. Why whouldn't it also take a while to figure out cryogenic treatment?

I'm not talking mouse-milk here, I am talking about being on the leading edge of a new process. All the nay-sayers out there remind me of those who bemoaned the AR-15 rifle because it was made of aluminum and plastic. We all know that REAL guns are made from wood and steel. These are the same type of people that say a barrel has to be round, when a fluted barrel of the same weight will ALWAYS be lighter, stiffer, and offer greater heat dissipation. That's not theory or hype, it's the truth on all three counts. These will be the same people that will delay carbon-fiber barrels with certain advantages and disadvantages from common use. These are the same people that cried foul when Glocks and Smith crunchentinkers replaced Revolvers. REAL cops carry revolvers, right? BAH, BAH, BAH... (time for another purple pill) :uhoh:

Sean Smith
January 12, 2003, 10:22 PM
Hate to do this, but.... Sodium Chloride is a MOLECULE by definition.

I hate to do this, but you are still wrong. Alot of people call ionic compounds "molecules," but that isn't correct. But don't take my word for it... even though I am a nuclear engineer.

http://www.chem.purdue.edu/chm200/formunit.htm

Solid salts such as sodium chloride (NaCl) exist as cubic crystals. Unlike a molecule, the amount of matter in a single crystal of NaCl can vary greatly. In that sense there’s not a constant amount of sodium and chloride in every crystal, so strictly speaking this compound shouldn’t be called a “molecule.” What does remain constant is the ratio of sodium to chloride ions: there is one sodium ion for every chloride ion. Thus, the smallest distinguishable structural unit that we recognize and use in formulas is NaCl, which we call a “formula unit.”

A formula unit is an amount of a substance, like an atom or a molecule, but more generic. We use the term formula unit when it is not proper to call a compound a molecule.

Emphasis mine.

So much for your "by definition." :p

romulus
January 12, 2003, 10:50 PM
Sean Smith...thanks for the illuminating lesson. Can't offer the same thanks for your contemptuous and arrogant tone, though...

Sean Smith
January 12, 2003, 11:07 PM
Sean Smith...thanks for the illuminating lesson. Can't offer the same thanks for your contemptuous and arrogant tone, though...

Gee, Romulus, last I checked you were the guy using a "contemptuous and arrogant tone" (and bad science) to try to discredit someone else. Oh, yes, here it is...

By Romulus:
The chemical and physical laws that apply to gems apply to all of earth's elements. Molecules are composed of atoms joined together by some sort of chemical bond, be it covalent, ionic, whatever. I fail to see how crystals of a particular metal are non-molecular, when all substance in this universe is either atomic or molecular, the latter being the preponderant case, as pure elements are rare indeed. Just my recollection of basic chemistry, that's all.

As far as metallurgy is concerned, is iron oxide not a compound and hence identifiable by a discrete molecular arrangement? Aluminum oxide? Copper sulfate?

Again no offense intended, but if your statements on the physical-chemical nature of steels are suspect, it follows that so are the ones you make on cryo stress relief...

Next time you want to discredit somebody (and, hey, the guy could be wrong about Cryo for all I know...) at least try to be right about SOMETHING in your argument. :D

In case it isn't obvious, I'm not "conteptuous" of people who don't know their chemistry. I'm "contemptuous" of people who try to discredit others when they obviously don't know what they are talking about.

Badger Arms
January 12, 2003, 11:12 PM
Alright, explain this statement of yours:

Sodium chloride and other ionic solids don't have molecules or atoms

Justify your statement. An atom is an atom regardless of the electron count. Concede that salt has atoms and I'll concede that, strictly speaking ;), salt does not have molecules.

Badger Arms
January 12, 2003, 11:13 PM
duplicate. Sorry.

mete
January 12, 2003, 11:19 PM
thank you Sean, now there are two of us.

Sean Smith
January 12, 2003, 11:22 PM
Ions are formed from atoms. They aren't the same as atoms. Thus, an ionic compound is made of ions, not atoms. That's all.

To make it clearer (I hope :D ): In covalent bonds, atoms share electrons insead of gaining or losing them, thus they don't become ions. So a molecule is made of covalently bonded atoms, and an ionic compound is made of former atoms that became ions.

If an ion was an atom, it would just be called an atom and not an ion. There are degrees of ionization, so in layman's the ions of sodium and chlorine aren't as "different" from the normal atoms as the ions of iron are in a metallic crystal lattice where all the electrons are basically "shared" across the electron "sea."

So it all sorta sounds like semantic, which it sort of is, only it really isn't, because it effects what the properties wind up being of the various compounds/ what-have-you.

mete
January 12, 2003, 11:22 PM
thank you Sean, now there are two of us.

mete
January 12, 2003, 11:24 PM
thank you Sean, now there are two of us.

mete
January 12, 2003, 11:24 PM
thank you Sean, now there are two of us.

romulus
January 12, 2003, 11:56 PM
.

romulus
January 12, 2003, 11:57 PM
Sean Smith, I just don't see how you can read in the above discussion any attempts to discredit, when objections were prefaced by the expressed intent not to offend. Beyond that, when someone uses words such as "suspect" and speaks of his "recollection" he is de facto admitting not to being an expert.

So the only lack of grace on this thread is yours.

Nevertheless grateful to have been set straight by you on the chemistry, ta ta,

Rom

Stealther
January 15, 2003, 12:38 AM
I've found this thread pretty enjoyable with exception to some of the ruffling of feathers and hope it continues, in a more constructive way that is. I don't know jack about this stuff so don't jump on my butt about this, just askin some questions!

Mete: How I interpreted what you wrote was that you felt that the cryo process is either totally useless or inefficent in relieving stress in metals when compared to heat treating/tempering? Let me know if I misunderstood.

If I did understand you, do you believe it is possible to obtain (using a heat process) the benefits/claims of people performing the cryo processes? If so, what is this process and could you refer us to a company that performs it?

Thanks again for the info, keep it clean!

whitebear
January 15, 2003, 09:04 AM
It always amazes me how these discussions so often end up taking the tone of conversations concerning the type of wood making up the True Cross.

It ain't religion, guys. Read the responses, research and maybe learn something.

"Can't we all just get along?"

romulus
January 15, 2003, 10:15 AM
I had the pleasure of touring Krueger Barrel yesterday...I saw their cryo tank.

I'd venture a guess that a barrel manufacturer like Krueger will do its homework before buying equipment and introducing new processes.

Really nice fluting on some of the barrels, too

mete
January 15, 2003, 11:59 AM
Stealther, I try not to waste words, so I wish you had read all of mine; 1- check Shilen website , first question under Q&A, 2- stress relief is done by heating. I am too old and smart to put up with the like s of Romulus, Badger and Nero like their using the old technique of first saying " I don't mean to flame" then proceeding to flame.

mete
January 15, 2003, 12:09 PM
Also read Rules of Conduct 4) Spamming , trolling,flaming and personal attacks are prohibited.

Stealther
January 15, 2003, 03:52 PM
Stealther, I try not to waste words, so I wish you had read all of mine; 1- check Shilen website , first question under Q&A, 2- stress relief is done by heating.

:scrutiny:
I wish you had read MY post before you made your reply, here is a recap

If I did understand you, do you believe it is possible to obtain (using a heat process) the benefits/claims of people performing the cryo processes? If so, what is this process and could you refer us to a company that performs it?

No need to get snotty, my post was complementary and I was simply requesting clarification and for you to go into more detail on possible heat treatment processes as an alternative to cryo treating. If that chip on your shoulder wasn't so big, you might have read that. :rolleyes:

mete
January 15, 2003, 07:48 PM
Its not the chip it's the patience wearing thin. To repeat a posting, stress relieving of steel is usually done between 900F and 1200F.If there are stresses in the barrel they will be relieved. Try to find a heat treat shop that knows something about guns. How much that would improve accuracy depends on the stresses. I would make no other claims ,that is wear resistance etc.

Watchman
January 22, 2003, 11:31 PM
Regarding fluting a barrel...

It seems to me that much of the stress imparted in a barrel comes from the method of machining used.

For instance, I have observed many times over the years that metal "bends" when it is machined in a certain manner. Lets use a keyway on a pumpshaft for an example. Sometimes milling a large keyway on one side of the pumpshaft causes the metal to bend in the direction of the keyway because the internal stresses that were put into the metal when formed are now uneven due to one side of the shaft being relieved.

Taking a piece of square precision keystock and sawing one side of it to make it rectangular will often result in the piece bending.

There are many examples of metal objects relieving themselves when machined.

I have also observed barrels that were being manufactured with fluting on them and have thougt that proccess was somewhat flawed. Most manufacturers will use a CNC lathe to flute the barrels as it is quick and accurate. What they will do is to cut a flute, turn the barrel 60 degrees (on a 6 flute barrel)cut another flute and work it around the barrel until complete. It seems to me that this allows an uneven relief of the natural stresses in the barrel which allows it to bend some.

I beleive if they used an opposing method, meaning that the barrel is cut and then turned to the opposite side and then a flute cut, and done this way each time a flute is cut that it would balance out the stresses that are built up in the steel through the manufacturing proccess. It may be that the Cryo treament is allowing the stresses in the barrel to normalize somewhat and balance itself out.

I dont claim to know anything about the chemcial makeup of steel or whether it has molecules or not, but I wonder if there is too much emphasis played on the chemcial and physical aspects of the steel and not enough about the way we handle barrels of precision rifles when they are being machined.

Comments?

Mute
January 23, 2003, 01:01 PM
The only PRACTICAL benefit from fluting a barrel is the weight savings. A well made barrel, whether cryo treated or not will last thousands of rounds and give more accuracy than most people are able to ring out of their rifles.

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