User Panel
Posted: 8/8/2001 5:41:14 AM EDT
I am wanting to get a varmiter upper for my AR, and was considering one of the one's Gunsmoke had advertised in a recent thread. It has a 24" stainless barrell,and for 40.00 more it can be fluted. This is going to be used for informal benchrest shooting, and yes I know that it won't compete with the bolt actions, but will the fluting help any with accuracy? If not, what benefit would it have?
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fluting increases the surface area of the barrell allowing it to cool faster and less weight. For slow fire this gives you a "cold barrell" shot with every trigger pull
jmho mike |
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This has been tested, articled, cussed and dis-cussed a lot. No, it will not increase rigidity. Yes, it will decrease weight (deep fluting took 14oz. off a 1'dia 24" AR barrel for me). Yes, it will cool faster, but the difference is so slight as to be academic. Yes (best reason to flute) it looks cool.
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Fluting works best on barrels made for larger calibers, .30 and above. If you get some custom .300 Win Mag rifle, fluting will be the most beneficial (especially for saving weight). On a .223, it does not help that much, except to save weight. As for barrel rigidity, it depends upon how the fluting is done and how the fluting changes the bending moment of the barrel.
Point: Don't bother fluting your AR. themao [chainsawkill] |
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My feeling is that you should save the additional $40 for ammo. There is a big discussion at Armalite's web site on this subject at [url]www.armalite.com[/url]. Of course for if you like it for aesthics, i.e. the "cool factor" go for it, but for practical reasons probably not worth the extra $40.
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Fluting works best on barrels made for larger calibers, View Quote Why would that be? What do you mean by "works"...since the only practical thing it does is reduce weight, and a larger caliber barrel of the same od is lighter already....? As for barrel rigidity, it depends upon how the fluting is done and how the fluting changes the bending moment of the barrel View Quote |
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Fluting will make an object more rigid. Dad is a PH.D. in metalurgical engineering. His current job deals with BeCu , berrilium copper, and shape and form and thermodynamics are all part of his job and education. The effect of the ridges on a cylindrical object do in fact stiffen the cylinder. These are facts proven by the science of physics. If you would like to dispute them you really need to go to a physics lab at an accredited university to dispute the laws of physics with others who are in the field of physics.
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This has been done to death...adding a ridge will stiffen a metal object. Creasing it to create a ridge will stiffen it. REMOVING metal will not make it stiffer.
And BTW...how does having a daddy with a degree make you smart? |
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A fluted barrel is more rigid than a non-fluted barrel of the same weight. A fluted barrel is less regid than a non-fluted barrel of the same diameter. Removing material can cause metal to warp. If the metal is removed after the fluted are cut there will be stressed that need to be relieved. When the fluted are cut the barrel can have a tendency to warp unless stresses are releived after each process.
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In case you havent realized this, removing the metal creates the ridge you yourself mentioned will stiffen the object. If I own a computer, odds are I have a phone, so calling someone that would know about the subject, as opposed to just spouting whatever verbal vomit comes to mind, is the best course. That is why this board is here to get information from reliable sources. So if a PH.D. of metalurgical engineering is not a good source for information regarding the construction and strengths of objects made of metal I may be wrong about the fluting concept. What you, obviously without a proper degree to discuss this topic, do not understand is the shape is what creates the strength. And actually, removing the metal in the form of fluting is better because you are not trying to adhere extra material to the object to give it a ridged form. Also the added surface area is better for heat dispersion.
As far as my personal intelligence goes, your obvious limited intellect is not impressive at all! Have a nice day and if for some reason you have the ability to use a library why dont you pick up a book or two on thermodynamics, physics, and metalurgical engineering. |
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A fluted barrel is more rigid than a non-fluted barrel of the same weight. A fluted barrel is less regid than a non-fluted barrel of the same diameter View Quote Thank you, very much. ("You're wrong 'cause my daddy's smart" I will be SO glad when junior high starts up again) |
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And the size is not as important as the shape of a structure. Pound for pound the fluting does end up more rigid than a nonfluted cylinder. Now as Guardian stated, process is the most important factor. If done wrong it can and will weaken the barrel. A square tube is not as rigid as a spherical tube same diameter, on the flat side of the square tube. The edges are stronger than the flat part. A sperical tube with ridges same diameter is a stronger shape because it has the best of both worlds.
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The next "can't live without" accessory for your AR will be a conversion kit containing a new "super" material that will completely fill those flutes and in the process create "velocity zones" around the outer surfaces of your barrel!
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I posed this same question to an professer in one of my college engineering course's during the short period that I was misguided enough to think I want to be an engineer.
His answer was that, if done properly, fluting will INCREASE the strentgh of the object. Fluting adds the ridges, as mentioned earlier and creates a shape that is more resistent to bending than an unfluted object of the same diameter. |
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From a structural engineering view, a tube of a given diameter will have a higher radius of gyration if it is light wall versus heavy wall. Fluting could accomplish the same thing, however a higher "r" means the tube is stiffer when used as a column. Conversly, lightening the tube will reduce the section modulus which will reduce the strength of the tube when used as a beam. I believe that a rifle barrel acts as a cantilevered beam, not a column, and fluting would have an adverse effect. I doubt that the effect amounts to much and since fluting does look "cool" I'd let appearance govern the decesion
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I am in total agrement with Highland Mac !! (I think...no, no, I'm sure.)
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Makorov, how about we use highpowered magnets that work on copper and lead to fill the fluting so we can get 5000fps out of mil surplus rounds!!!
[beer] |
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That is interesting....I have known for years that flutting is much harder than non-flutting....But nobody ever explained to me this way. Thanks....Good to know.
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I must really be a dumbshit. You guys lost me entirely--I'm still trying to figure out how fluting "looks cool" when most of the fluting is done behind the gas tube port and is covered by the frigging handguards. I have only seen fluting on one rifle done in the short section between the muzzle and front sight.
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Critter,
I'll not wade in on the fluting question, but I will put mine, Dad's, uncle's or Mentor's 24" Elite barreled CR6724 up against any stock (Non-custom made Krieger barreled) Rem700 Police/Varmit/Sniper rifle, so don't sell a good match AR short. In the right hands w/ the right load, scope & trigger, up to 800 yds only the new Krieger custom made bolt guns will outshoot any of the 4 indentical ones listed. Mentor bought 2 rare 700 police hvy. barreled in Jan. thinking they'd do better and sold 'em both by end of Feb. |
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Quoted: This has been done to death...adding a ridge will stiffen a metal object. Creasing it to create a ridge will stiffen it. REMOVING metal will not make it stiffer. And BTW...how does having a daddy with a degree make you smart? View Quote Sorry, IT does make it more rigid. Country boy explanation, When you hold a peice of paper horizantal with one hand, you can put a curve in the paper and it will support itself and not fold down. Do they teach metal shop in jr high and high school anymore? They forced me to take the class and to beleive I would everneed to know the stuff. GG |
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Celt, Think about an I beam in a building. It is much stiffer pound for pound than a solid steel beam of similar dimension. Whether it makes a difference in 26" or so, I could'nt say. I'm sure you can think of other analogies also. just my .02 cents.
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Of course it is. POUND for POUND. That was never the question.
Yes, the paper is stiffer once you're creased it. That was never the issue. Yes, some shapes are stiffer than others. No one disputed that. Cut a groove out of the paper. Mill a slot down the beam. NOW what do you have. |
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Let's learn to interpret information correctly. Fluting will give you more rigidity than a non-fluted barrel OF THE SAME WEIGHT. However, if you take a bull barrel of a given weight, say 5 pounds and flute it, shaving your weight to say, 3.5 lbs., the heavier barrel will be stiffer.
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The truth is the diagonal cross section is inversley proportional to the pi R squared dimetral pitch. Divide that by the obtuse plasma heilcoloid and add the flutings bi lateral quanitfication you see that the asnwer is quite obvious....duhhhh....
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Mute, the weight or mass is not as important as the shape. The shape is the key. The best example here is the I beam. It is much lighter than a solid beam of steel same size, but has much more structural rigidity than a solid piece of steel.
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Garandshooter and HighlandMac, you had better listen more closely to your instructors or find others. The key is the amount of material used to manufacture the barrel. Given the same amount of material, the fluted barrel will be stiffer than non fluted. However, fluted barrels are created by removing material and decreasing the cross sectional area. I will first try to put this in layman terms. A tube is stronger than a solid cylinder WITH THE SAME MASS. Taking a cylinder of plastic and hollowing it into a straw, making it into a tube, does not increase it's rigidity. Taking a solid beam of steel and cutting out the sides into the shape of an I-beam does not increase it's rigidity. For those of you with a physics background I will return in a little while and get into Young's modulus and the relation between stress and strain on a solid.
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HighlandMac, by your hypothesis a solid beam of aluminum one foot in diameter is not as strong as an I beam made out of tin foil (also aluminum) of the same diameter. You could cut the solid beam of aluminum down to an I beam with the thickness of tinfoil. Tell me how that increases its rigidity.
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Ok, of 2 barrels with equal weight one being fluted the other non-fluted, the fluted is stonger. We all agree to that. So if weight is the key, and you remove weight from the stonger fluted barrel, but not enough weight to make it weaker than the other barrel, you end up with a lighter weight, stronger barrel. That is the point of doing it. How much stronger is the fluted barrel with equal weight to the non-fluted barrel? If it is known that there is a significant difference in strength, taking away some of the weight from the fluted barrel will leave you with a stronger and lighter barrel.
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AR15, we are talking about the same materials used in both objects. A solid beam of aluminum would not be as rigid as an "I" beam shaped peice of aluminum. In this case Youngs Moulus would not apply because we are not trying to alter the length of the object. We are comparing the rigidity of the object, not trying to determine how much force is required to change its length.
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AR-15, are you taking into account the change in shape and the effect that it has?
If you take an I beam that has way too much mass in the center and not enough on the top and bottom, you can reshape it to a more efficent design, making it stronger, while at the same time doing away with some weight. If I take a cylinder and mill it to become an I-beam, what will be stronger? What shape is more resistant to bending. BTW, on a fluted barrel, wouldn't the radius be unchanged? I am no expert, so I am here to learn ..... |
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A structural engineer just wrote and article that appeared in last month's Precision Shooting. Using computer modeling, he showed that fluting increased rigidity significantly, increased cooling area but [b]not[/b] significantly, and reduced weight. His conclusions:
1) Fluting was most indicated when reduced weight was needed in a barrel of a given contour 2) Fluting may be indicated if increased rigidity is desired in a barrel, however there is no evidence that the increased rigidity improved accuracy; in fact, there is considerable evidence that fluting can adversely affect accuracy. This study in no way addresses the "chick factor", that is fluted barrels look cool, therefore increasing the chance of attracting babes. the shooter [smoke] |
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HighlandMac
Turn that I beam sideways. It's the material at the greatest distance from the axis you are concerned with. |
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Wow, a lot of response on this one. Thanks for the input. t is certaily confusing, but even those that feel fluting makes the barrell more ridgid never mention that it makes it more accurate. I think I'll save the 40.00 dollars, and put it towards improvements on accuracy. Thanks guys.
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Hey, can we toss in some opinions regarding other topics in addition to the current thread. Anyone got some thoughts on;
Do .223Rem and 5.56x45mm rifles have the same chamber dimension? or Do Bullets develop LIFT during their short flight? How about Which rifle/round would you choose to hunt runaway dinosaurs from J.P.? and lets not forget Which is better a chromed-lined G.I. barrel or a stainless steel CMP tube? HEHEE - This post will go on forever! |
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Garand_Shooter: ,,,,during the short period that I was misguided enough to think I want to be an engineer. -------------------------------------------------------------------------------- thebeekeeper1: I must really be a dumbshit.... View Quote LOL! Don'tcha you just love "pop engineering"? Garand_Shooter, I was misguided enough to think the same thing (sssshhh! - Don't tell Chicago Bridge & Iron that, they still haven't discovered the truth, & I NEED the money). "Mute" is getting pretty close to identifying, and lighting up the problem here. [i]Or should say the "baseline definition" misunderstanding?[/i] |
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HighlandMac, aluminum foil is the same material as an aluminum beam. If you take a solid beam of aluminum 10 cm across and cut it into an
I-beam with the thickness of each length equal to that of paper it will crush quite easily. Also, you are correct in stating that Young's modulus is the lengthwise stretching of a solid. A barrel, when fired, is an applied force to one end of a tube thus compressing and stretchhing it. The up and down vibrations are secondary. The explosion is in fact changing the barrel length. Because no mass is perfectly rigid and equally dense with molecules perfectly aligned, the wave going down the barrel will travel at an uneven rate, creating transverse waves. Garandshooter, the cylinder will be stronger than the I-beam milled from it. The key is milled from it. If you took a bar and made it into an I beam the I beam would be stronger assuming you used all the material. Also, the radius would be the same to the edges of the flute, but to the inner part of the flute the radius would be less. I will try a simple explanation again. If you have a barrel and cut one flute in it will it become more rigid? How about if you cut 100 flutes in it? Would it then become a lot more rigid? If you cut that many the thickness of the flutes would be paper thin. How rigid is this? Try this analogy, the shape of the folds in a radiator make it stronger than if that same amount of material was in a flat sheet. However, a radiator is not as rigid as a solid block of metal with the same dimensions. |
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I know I'm just the board dumbshit, but I'm the only one who asked a question that hasn't had 14 different answers. How is a bbl. "way cool" or "more cool" by having flutes cut if they are hidden by the handguards? I am very perplexed.
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Hey, I'm back. I was just on my way out when I made my last post and thought how I could explaine this all the way home.
Here goes. Try 1. The factors that will determine the deflection of any object are the strength of the material and the dimensions of that material, relative to the direction of the force applied to it (moment). Every shape when viewed about its axis will have something that is called it's moment of inertia. Take the I beam. It has a very high moment of inertia about an axis that is vertical with regard to the way one normally considers it in use. Take a 2 X 10. It's pretty ridged when cantilevered on end, vertically. Bends like a wet noodle when cantilevered on its side. Now if you took 2 I beams, or 2, 2 X 10s and fastened them in an "X" fashion you would now have a beam that was pretty stiff in 2 directions, both vertically and horizontally, but it would still bend easier on the 45 degree angles. Take this to it's logical conclusion. |
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Try 2.
Take your piece of paper and fold it and you have stiffened it, but only in one direction. That same piece of paper would be the most ridged, flat vertically, when resisting a vertical force. Again it is the moment or the added advantage, due to a lever type of action, (torque), that gives it, it's strength in that vertical direction. The greater the distance from that moments center, the greater the mechanical advantage. Do you now see that a perfect circle, given the same amount of material, will provide the maximum resistance, IN ANY DIRECTION, for any shape? |
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Quoted: I know I'm just the board dumbshit, but I'm the only one who asked a question that hasn't had 14 different answers. How is a bbl. "way cool" or "more cool" by having flutes cut if they are hidden by the handguards? I am very perplexed. View Quote Many of the barrels are fluted full length (before & after gas block), here's an image of my BM V-Match - [img]http://albums.photopoint.com/j/View?u=106997&a=781907&p=52711942&Sequence=0&res=high[/img] |
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In that case--[b]very cool[/b]. Thanks! Mine is only done under the handguards. [:D] & [}:D]
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If you have 2 h bar barrels and you flute one of them the fluted one is more rigid, only if the flutes are exactly equidistant apart and the sane depth and etcetera. If they are not EXACTLY the same, all is lost. Also the fluted barrel will cool faster due to more surface area
GG |
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So, a fluted barrel done correctly, is more rigid. And again, 2 barrels of equal mass, one being fluted is stronger. If the mass is reduced to the point were the fluted barrel is still stronger, and now lighter that would be a better barrel. That is my point.
Of course if you cant shoot worth a shit a toiletpaper roll would work just as well!! hahahahah [beer] |
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Now, what about the theory of a rigid barrel being more accurate?
And if you were going to hunt dinosaurs in JP your best bet would be an A-10 warthog with the massive rotary cannon on the front so one would not have to get too personal with the dinosaurs!! [beer] |
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Quoted: And if you were going to hunt dinosaurs in JP your best bet would be an A-10 warthog with the massive rotary cannon on the front so one would not have to get too personal with the dinosaurs!! View Quote [b]Barrel fluting not required -[/b] [img]http://albums.photopoint.com/j/View?u=106997&a=8395959&p=47670590&Sequence=0&res=high[/img] |
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[url]www.cavalryarms.com[/url]
Flute It.[;)] [img]wsphotofews.excite.com/011/gr/Cp/yX/xr58552.jpg[/img] |
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Think of it this way: a steel I beam that has been fluted will be proportionately weaker than a paper barrel of the same wieght if it has been turned on it's side.
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