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Posted: 1/21/2003 4:20:37 PM EDT
| I am planning on ordering a XM15 E2S Shorty A3 Bushmaster. I've been thinking of ordering it with a fluted barrel for a little weight savings, are there some drawbacks to this I'm not thinking of? Anyone else shooting a setup like this? |
| A fluted barrel will heat up faster than a non fluted barrel of the same diameter. A fluted barrel is not as rigid as a non fluted barrel of the same diameter. That said for a carbine there is no use for anything heavier than an M4 in a semi auto and most people would be beter off with a lightweight barrel. |
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NE, after you've been around here for awhile, you're gonna want one of everything. I have an HBAR, an M4, and have just ordered a LW pencil barrel, all 16", all Colt. The HBAR shoots better than the M4, but that might be just an individual barrel question. If I were you I would be tempted to start with a Lightweight. |
| What DevL said about the fluted barrels is true, but barrel weight is probably more important to you than diameter. A fluted barrel will cool faster and is more rigid than a solid barrel of the same WEIGHT. But a fluted barrel will probably still weigh more than a lightweight profile barrel. If you could turn and flute a a normal barrel to the same weight as a M4 barrel you would have a more rigid and faster cooling barrel, but I suspect that to do so would make the barrel walls to thin at the bottom of the flutes. |
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I'm not an expert, but wouldn't a fluted barrel cool faster/heat up slower than a non fluted barrel of the same diameter because of the extra surface area?? Although I haven't taken temperature readings, I think my fluted barrel heats up much slower than my HBAR. My lightweight barrel gets hot fast!!! I love both my fluted and lightwieght barrels, they both serve their purpose. The fluted barrel is much lighter than the HBAR, but the lightweight barrel is about a half pound lighter than the fluted. If I had to choose one barrel it would be the fluted barrel (more accurate, stays cool, still pretty light, and looks good). You have to have both! |
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I ordered a 16" fluted HBAR and before it arrived I found a good deal on a 16" M4 upper with a fake flash hider. Bushmaster agreed to take back the fluted HBAR, but it was such a nice piece of work I decided to keep it anyway. Like Geohans says, after a while you'll probably want both. After all this is a disease.[:D] The fluted HBAR shoots and looks great, and I prefer it to the lightweight or the M4 without a flash hider. Theorecticaly it is also stiffer than both and I am a typical varmint rifle / accuracy buff. Now my wife misses the lightweight Colt - oh well!! |
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Quoted: I'm not an expert, but wouldn't a fluted barrel cool faster/heat up slower than a non fluted barrel of the same diameter because of the extra surface area?? Although I haven't taken temperature readings, I think my fluted barrel heats up much slower than my HBAR. No the rate a barrel heats up is due to its mass. The fluted barrel heats up faster because of lower mass but because of its greater surface area it cools faster too. Problem is it will reach a higher peak temp due to it its lower mass so it negates much of that cooling advantage. Fluting is superior if the weight is the same but if they are the same diameter fluting only helps reduce weight. Resistance to heat, rigidity and accuracy will all suffer at the expense of weight. That said you cant tell the difference in accuracy from a LW chrome lined AR barrel from a HB chrome lined barrel until you have fired a couple of mags through them and the light weight heats up. Fluting wont hurt accuracy there but there are better alternatives if you just want a light weight barrel. In testing the military did not find that a HB was any more acurate than the A2 profile barrels even when heated from long strings of fire. This was due in part to the limitations on accuracy imposed on milspec barrels. It would be different for match barrels however. IMHO Military barrel - light under the handguards heavy out front or lightweight barrel Match barrel - fluting for sure |
| Whoa there friend, you seem to have it all back-asswards. The fluting provides more surface area to conduct heat away from the barrel thus will remain cooler then a non-fluted barrel. Also, fluting creates stregnth in the barrel makeing it stiffer than a non-fluted barrel. For 50 bucks you get a lighter, stiffer, cooler barrel. Is it worth $50, I do not know. But it is quite an improvement. |
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I've got a BM fluted 16" V-Match and a BM LW 16". The LW barrel gets hotter faster but is significantly lighter than the fluted barrel. The fluted barrel dissipates heat quickly and shoots much more accurately than the LW. I have the fluted barrel for coyote hunting and I bought the LW just because I think it looks good and it's extremely light. |
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Quoted: Also, fluting creates stregnth in the barrel makeing it stiffer than a non-fluted barrel. This is false. You cannot remove material and add strength. It is true that a fluted barrel will be stiffer than a non-fluted barrel OF THE SAME WEIGHT AND LENGTH. That is a vital distinction, but one that does NOT apply to this situation, as the barrels being discussed are of different weights. -Troy |
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Quoted: Whoa there friend, you seem to have it all back-asswards. The fluting provides more surface area to conduct heat away from the barrel thus will remain cooler then a non-fluted barrel. Also, fluting creates stregnth in the barrel makeing it stiffer than a non-fluted barrel. For 50 bucks you get a lighter, stiffer, cooler barrel. Is it worth $50, I do not know. But it is quite an improvement. Go re-read my post. BARREL MASS determines how fast it heats up and surface area how fast it cools. Yes the fluted barrel will cool faster but if material is removed it will get hotter faster and reach a higher peak temp given a certain number of rounds fired continuously. This largely negates the advantages of fluting as far as making your barrel cooler. You cant remove material from a barrel and make it stronger. That is common sense, come on. Fluting a barrel of the same diameter as a non fluted barrel weakens it and makes it less rigid. If you took a larger barrel and fluted it to make it the same WEIGHT as a smaller non fluted barrel then it would be stiffer than the same weight/smaller diameter barrel. |
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Quoted: So what you guys trying to say, my A2 profile fluted 20" is going to be not very accurate. I don't think we made any predictions about your specific configuration. In fact, I'm not even sure what configuration you're referring to. Do you mean a 20" A2, with flutes on the front, heavy portion? Or something else? Where's does a free-floating handguard come into play when that light barrel heats up? Any barrel will lose strength as it gets beyond a certain temperature. When that happens, barrel whip is more pronounced, and accuracy is reduced. Barrel profile, barrel length, steel alloy used and other factors all play into this equation. If you're looking for a barrel that will hold its accuracy at high temperature, you'll want a heavy barrel made from steel that retains its structural strength at as high a temperature as possible. That's why machinegun barrels are heavy and made with 4150 steel. But even they have to be changed out or watercooled to increase the rate of sustained fire. Free-floating prevents things from touching the barrel, which changes the way a barrel vibrates when a shot is fired. A free-floated barrel will vibrate more or less the same for every shot, contributing to better accuracy. If your barrel temperature has exceeded its structural strength limit, it won't matter much if its free-floated or not. It will lose accuracy. But put all of this in perspective. Unless you are firing full-auto, bump-firing, or just shooting round after round on semi as fast as you can, it isn't going to be an issue. And even if you are, you certainly don't need to worry about sub-MOA accuracy, because you're probably not *aiming* under 10 MOA. -Troy |
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If you have a tappered barrel, heat fllows in the direction of the thinest part of the steel. If the M4 barrel were fluted where it is thin in the center, the barrel will be stronger than the current M4, yet take longer to heat up plus the fluting acts as cooling surfaces for longer barrel life. That has been proven on many various MG's. Micro fluting is the most effective in cooling as there are more surfaces to provide the cooling, but fluting does cost more. Good Shootin, Jack |
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Quoted: So what you guys trying to say, my A2 profile fluted 20" is going to be not very accurate. Where's does a free-floating handguard come into play when that light barrel heats up? No, the inherent inaccuracy of chrome lined heavy barrels is such that fluting or turning thin under the handguards will not have any adverse effect on accuracy until it heats up. Even if its turned down under the handguards and fluted out front it wont have an effect because of the relative inaccuracy of the base barrel. Like Troy said if you have it heated up that much you are not firing for accuracy anyway. If you are referring to a cold bore shot then govt profile, fluted or heavy barrel will not make a difference in a chrome lined barrel to any noticable degree. If we are talking about a match barrel then things change. As far as the free float most everything has already been stated including the need for 4150 steel but remember if you want to decrease heating, the barrel needs to be able to circulate air efficiently. Something like the FF RAS will give you excellent cooling while the solid free float tubes will trap heat negating the effects of your fluted barrel since cool air cant come into contact with the flutes. As far as the fluted M4, it would be better at resisting heat but would be heavier also. |
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DevL, You sound like you know what your talking about and your probably right. But, I have an HBAR and a fluted HBAR of the same diameter and I would almost swear in a court of law that the fluted HBAR stays cooler for much longer. Of Course maybe it could be my subconscious trying to justify the extra $50 bucks. [:D] One thing's for sure, it does look cool (IMO) and that's got to be worth $50 bucks, right? The lightweight barrel is cool too! But for some reason I don't like that notch in the M4 barrel, I know it's military and all but I just can't accept it yet, but maybe I'll have to get one to see if it will grow on me [;)]. Kinda looks like it's been circumcised. |
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I surely did read your posting. Talking about comparing barrels of the same outside diameter, one fluted one not. More mass means that the barrel can absorb more heat before reaching a certain temp (and will retain the same heat longer). The increase in surface area for heat transfer of a fluted barrel (quoted as up to 80% more) more than offsets the mass effect and results in a cooler barrel all of the time (with the exception of full auto fire over long periods which will overpower any barrels ability. Regardless of weight, heat soaking will occur at some point and only surface area will help lower temp, the more the better.) Once the barrel gets hot the efficiency of heat transfer from the barrel to the surrounding air governs how hot it will get. More mass will not change that. As for stiffer, a barrel of the same outside diameter, when fluted, will be stiffer that one not fluted. The old saw that more weight makes something stronger is just myth. Shape has much to do with the strength of an object for its intended use. You can prove this by making a cylinder out of paper perfectly round and one made of paper folded to represent flutes. The fluted cylinder will support more weight as it is "stiffer". (That is why the sides of your car probably have many creases molded in, as it makes the body stiffer without weight.) I looked at a couple of high end barrel makers and found the following comments: From Krieger Barrels FLUTING Fluting is now available for Target, AR-15 Varmatch, Palma, and Sporter Barrels. Fluting increases rigidity and reduces barrel vibration and whip. Also, by exposing more exterior surface area, it aids in cooling your Target or Varmint Barrel. The flutes will start approximately 5 inches in front of the receiver and end approximately 2 inches from muzzle for mounting sight base or barrel band. A skip in one flute can be incorporated at 7.200 inches from receiver to mount scope base. From Lilja Precision Barrels Fluted Barrels Fluting barrels for both competitive target and hunting rifles is quite popular. There are two advantages to using a fluted barrel. Improved accuracy is one advantage because of increased barrel stiffness. (...) Another advantage to fluting is the increased cooling rate of the barrel because of the greater amount of surface area exposed to the air. Look at the radiator in your car. Is it high mass and low surface area? Of course not, just the opposite. It is a device to conduct heat away from itself. It is relative low mass metal with great surface area. If a higher mass would help then radiators would be made of iron. Look also at utility poles made of steel. They are not round as that is not the stiffest shape. They are octagon, which is much like fluting in shape. This contributes to the stiffness of the pole. There are still people that think iron ships cannot float and planes cannot fly. Go figure. |
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jdmcomp, Okay, I'm with you on the cooling thing. That makes sense to me. But,I'm a little confused on the rigidity thing. From what has been thrashed out on the forum here is that if you flute an HBAR you will loose rigidity because you are loosing material, and the unfluted HBAR will be more rigid. If you turn down a barrel and remove the same amount of material as the fluted barrel (but this barrel just has smaller diameter and same weight as the fluted). The fluted barrel will be much more rigid than this turned-down barrel of the same wieght. Your paper analogy makes sense but is this comparing paper of the same wieght or will the folded paper be more rigid than a cylinder of paper that has 20% extra wieght (thicker paper)???? Similar to an HBAR and a fluted HBAR (I think fluting removes 20% of the mass of an HBAR). |
| Don't be concerned with the thickness of the barrel for stiffness. Shape is everything. The bending (or more correctly wipping motion) of the barrel when you shoot is what we want to control. Each of the raised areas of the barrel created by the fluting is a supporting ridge which when the barrel tries to bend resist that force. (they have a different radius so bend at a different rate and thus create a resistence to bending overall) In a sense, the ridges are barrel reinforcements and since they bend at a different rate than the tube of the barrel they create a secondary resistence to bending. (think of the barrel as a tube with a series of reinforcing strips of steel attached to make it stiffer rather than a fluted barrel.) Just as the paper tube is stronger for pleating, the barrel is also. Even using the same weight of paper. The whole idea is to get the proper shape for the greatest stregnth for the use intended. The truth is that there is really little useful difference in accuracy or durability or any other area except in lighter wieght of the gun. The extra expense gets you less wieght and little else. Well, it does look sexy as hell. By the way, I have a Govt Model Colt and a home built fluted carbine. My guess is that with the same ammo, both will shoot better than 99% of those who would shoot them. Good discussion. |
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Howdy all, I've been an avid reader of the posts on this site for a while. Untill now, I've never felt compelled to make a post of my own but there are a few misconceptions regarding barrel fluting that I'd like to clear up. Firstly, barrel fluting does not make a barrel stronger. It makes a barrel stiffer in the sense that DURING FIRE, there are fewer atoms near the outer radius of the barrel to interact with each other. Energy transferred through the barrel causes atoms to bump into eachother (these atomic interactions are the source of heat). It is best that these interacions occur as close to the bore as possible, reducing whip. Barrel fluting does NOT make the barrel stronger as a member. Engineering stress due to axial and shear loading is inversly proportional to cross sectional area. For a given load acting on a member, decreasing cross sectional area increases stress. Engineering stress due to torsion and bending are dependent on both cross sectional area and moments of area. Again, less cross sectional area makes the member weaker. However, here is where the moments of area come into play. (Different moments of area are called different things. For example, the second moment of area is called the moment of inertia... this probably sounds familiar to many.) Anyway, moments of area are dependent on the shape of a cross section. Changing the cross sectional geometry therefore has an effect on the strength of the member. This is why some shapes are "stronger" than others. However, simply reducing the area of a cross section (fluting) will NEVER make a member stronger. Aside from the obvious reduction of cross sectional area, the effect on the moment of inertia is also detrimental to the member's ability to endure stress. Engineers use members of specific shapes to save weight. I-beams are used in bridges and buildings because they are very strong for their weight. They are NOT stronger than a solid beam with the same outside dimensions; they are weaker. However, the loss in strength is negligible compared to the immense weight and material that is saved. Regarding the paper example: Think about the case where paper is added to the outside of the 'splined' paper 'cylinder', in between the creases. If enough paper is added, eventually the cylinder would be round on the outside and would no longer be splined, just like an un-fluted barrel. Would the paper cyliner then be weaker? Of course not; the added material would make it stronger... it would pretty much be a cardboad tube. It is absolutly true that the idea of 'added WEIGHT=added strength' is false. However this is absolutly NOT an issue of weight, its an issue of cross sectional area. If area is added to the cross section of a member, it makes the member stronger. Likewise, and of significance when in comes to fluting, area REMOVED results in a weaker member. Again, a fluted barrel may be 'stiffer' in a firing situation (less barrel whip). However, it will not be STRONGER than a barrel of the same diameter that doesn't have flutes. Anyone still in doubt? Take an old Hbar and an old fluted Hbar to materials engineering lab and subject the barrel to any load you like. The fluted barrel will always fail due to a lighter load. Regarding the heat dissipation properties of a fluted barrel, yes, a fluted barrel will cool faster than a similar non-fluted barrel. There are a number of criteria to keep in mind regarding cooling properties. An engineering thermodynamics textbook is a good place to learn more. Also, an engineering mechanics textbook would be a good place to learn about stress, strain, etc, as it relates not only to barrels but other firearm components. Anyway, I hope that is helpfull. Also, I hope this post, my first, won't blacklist me as an 'obnoxious geek.' ;D Regards, Gil :) |
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Quoted: From what has been thrashed out on the forum here is that if you flute an HBAR you will loose rigidity because you are loosing material, and the unfluted HBAR will be more rigid. If you turn down a barrel and remove the same amount of material as the fluted barrel (but this barrel just has smaller diameter and same weight as the fluted). The fluted barrel will be much more rigid than this turned-down barrel of the same wieght. Ridge you are correct in your assumptions. jdmcomp no offense, but you are mistaken. I see the quote from Kriegers website used over and over again by fluting proponents and it misleads people. I wish they (Krieger) would either clarify or remove it. If you take an existing barrel and remove metal from it either by fluting, or turning down the o.d., it [b]will[/b] lose rigidity. Any first year engineering student can tell you that. If you compare two barrels of the same weight and length, one fluted, one not, as mentioned earlier by [b]Devl[/b], the fluted barrel is stiffer, Why? Because it has a larger o.d. If you compare two barrels of the same length and o.d. the non-fluted one is stiffer due to having more mass. If you want to lighten a barrel, fluting is the best way to go because you lose the least amount of rigidity from the loss of mass. This horse has been beaten to death over and over again at Benchrest.com. Speedy Gonzalez of SG&Y Rifles, a noted benchrest gunsmith performed a strength test on a barrel before and after fluting. Fluting caused the barrel to deflect more when a weight was hung from the muzzle. Fluted barrels are NOT commonplace in benchrest. Some shooters do use them, yes. Skip Otto is one who does extremley well with one. He does his own fluting and says that he uses tools that are sharp enough to cut your finger on and cuts very small amounts on each pass. That way he does introduce [b]any[/b] stress into the barrel. Adding stress to a barrel from the machining involved in fluting is the main reason benchrest guys don't flute. Shilen barrels says that if you flute one of their barrels the warranty is void. I would flute before I turned the o.d. smaller. It will retain more of the barrels original strength and it has the "cool factor". But I would only flute a barrel that was not a target barrel, unless Skip Otto did it [:D]. |
| Gil, you use strength and stiffness interchangeably in your discussion. Not correct. Sure, shear forces would find a round barrel stronger but who sees shear forces when firing a gun. Same for deflection. A barrel should have strength to withstand the forces it needs to withstand and forget the rest. Unless you use an M-16 as a pike or crowbar stronger just does not matter. I guess you Maine guys never give up ("nothing too strong ever broke"). Notice we agree that the barrel is stiffer. |
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So let's say we start with 3 HBARs. The first one we leave as an HBAR. The second one we flute, keeping the same outside diameter but reducing weight. The third we turn down until it's the same weight as the second one. If we use the barrel as a prybar, the 3rd barrel will bend easiest, then the 2nd one, and then the 1st one. But the difference between the 2nd and 1st barrels will be slight compared to the difference between the 3rd and 2nd. If we dump several 30-round mags through each on full-auto, the 1st barrel will be cooler [i]at the end of the string[/i] than the other two because it has more mass. The 2nd & 3rd ones will be the same temp. The 2nd barrel will be more accurate than the 3rd barrel becaue it'll bend less, but it won't be any more accurate than the first one, and should be a little worse. Now [i]wait 10 minutes[/i] and the 1st barrel will be hotter than the other two because it has more mass to hold the heat. Will the 2nd one be cooler than the 3rd one? I think so, because of the greater surface area, but maybe not that much because the mass is the same. |
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Quoted: Don't be concerned with the thickness of the barrel for stiffness. Shape is everything. The bending (or more correctly wipping motion) of the barrel when you shoot is what we want to control. Each of the raised areas of the barrel created by the fluting is a supporting ridge which when the barrel tries to bend resist that force. (they have a different radius so bend at a different rate and thus create a resistence to bending overall) In a sense, the ridges are barrel reinforcements and since they bend at a different rate than the tube of the barrel they create a secondary resistence to bending. (think of the barrel as a tube with a series of reinforcing strips of steel attached to make it stiffer rather than a fluted barrel.) Just as the paper tube is stronger for pleating, the barrel is also. Even using the same weight of paper. The whole idea is to get the proper shape for the greatest stregnth for the use intended. The truth is that there is really little useful difference in accuracy or durability or any other area except in lighter wieght of the gun. The extra expense gets you less wieght and little else. Well, it does look sexy as hell. By the way, I have a Govt Model Colt and a home built fluted carbine. My guess is that with the same ammo, both will shoot better than 99% of those who would shoot them. Good discussion. "Don't be concerned with the thickness of the barrel for stiffness." [b]NO, NO, NO NO, NO, [/b] The whole idea is to get the proper shape for the greatest strength given the about of weight or material that wishes to be removed. Get a Strength of Materials book. You need to model your "bending motion" in two different scenarios: 1): brute bending stress on the barrel, i.e. using the barrel to open a crate. Fluting does not increase the strength or “create a resistance to bending”. Lets make weight a constant or a requirement in a hypothetical barrel design. A fluted barrel with a greater OD, which also weights the same as a non-fluted barrel with a smaller OD, will be stronger on every perpendicular axis. Strength is lowered if any two flutes are 180 degress apart or have another flute 90 degrees from it. Notice the flutes are never 180 degrees apart from one another. 2): small signal stress, barrel whip and harmonics Fluting does not limit, inhibit, or lower barrel whip. Fluting a barrel actually ADDS different order harmonics, which resonate in the barrel after a shot In other words, a fluted barrel is more “noisy” in a vibration sense, that a non-fluted barrel. Each of the raised areas of the barrel created by the fluting is a supporting ridge which when the barrel tries to bend resist that force. (they have a different radius so bend at a different rate and thus create a resistence to bending overall) The raised area is the part of the barrel that was not machined off! The now fluted barrel is not stronger than it was previous to the machining. If you want to get real technical, the profile and machining and the sharpness of the mill has an effect on the strength of the product. You cannot remove mass and build strength; you can find clever ways to remove mass without greatly compromising strength, i.e. fluting a barrel. Just as the paper tube is stronger for pleating, the barrel is also. Even using the same weight of paper. The pleated tube has more material and mass in it, the wall thickness is constant between the pleated and non-pleated. |
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Quoted: Whoa there friend, you seem to have it all back-asswards. The fluting provides more surface area to conduct heat away from the barrel thus will remain cooler then a non-fluted barrel. Also, fluting creates stregnth in the barrel makeing it stiffer than a non-fluted barrel. For 50 bucks you get a lighter, stiffer, cooler barrel. Is it worth $50, I do not know. But it is quite an improvement. NO, [puke] You have it ass-backwards. Yes, there is more surface area. The extra surface area provided by fluting is usually not enough to significantly improve barrel cooling. REMEMBER, the barrel used to once have the same OD in it's entire circumferance, there is little added surface area. From a thermodynamics standpoint, mass does not effect cooling rate. In other words, a fluted barrel may [b]slightly[/b] cool better because of it's increased surface area, (which in our case it ONLY after the front site!!!!) However, there is a increased peak temperature of the muzzle area because of less material or mass. Again if you want to get real technical: Do we all know that increased temperature causes thermal expansion of metals? There will be more thermal-mechcanical stress in a fluted barrel because the "islands" will be cooler than the "lands" causing uneven expansion. If every flute is itentical, the forces should cancel out but, they never do 100%. The arguments and claims by manufacture's are only valid given a fluted barrel compared to a barrel of small OD and the SAME MASS. There is a billion posts on barrel fluting. |
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Quoted: I surely did read your posting. Talking about comparing barrels of the same outside diameter, one fluted one not. More mass means that the barrel can absorb more heat before reaching a certain temp (and will retain the same heat longer). The increase in surface area for heat transfer of a fluted barrel (quoted as up to 80% more) more than offsets the mass effect and results in a cooler barrel all of the time (with the exception of full auto fire over long periods which will overpower any barrels ability. Regardless of weight, heat soaking will occur at some point and only surface area will help lower temp, the more the better.) Once the barrel gets hot the efficiency of heat transfer from the barrel to the surrounding air governs how hot it will get. More mass will not change that. False, you are violating more than the 1st law of Thermodynamics. The heat or total energy will conduct into the barrel until it reaches thermal equilibrium and all parts of the barrel are the same temperature. If you add mass to the barrel, the equilibrium temperature will decrease as there is more material to “hold” the heat. For the temperature or remain the same you would need to add more energy or heat to the more massive barrel. As for stiffer, a barrel of the same outside diameter, when fluted, will be stiffer that one not fluted. The old saw that more weight makes something stronger is just myth. Shape has much to do with the strength of an object for its intended use. You can prove this by making a cylinder out of paper perfectly round and one made of paper folded to represent flutes. The fluted cylinder will support more weight as it is "stiffer". (That is why the sides of your car probably have many creases molded in, as it makes the body stiffer without weight.) False. Body panels with creases are more rigid, HOWEVER, Mass is constant. This analogy does not apply, same with your light poles and fluted cylinders. I looked at a couple of high end barrel makers and found the following comments: From Krieger Barrels FLUTING Fluting is now available for Target, AR-15 Varmatch, Palma, and Sporter Barrels. Fluting increases rigidity and reduces barrel vibration and whip. Also, by exposing more exterior surface area, it aids in cooling your Target or Varmint Barrel. The flutes will start approximately 5 inches in front of the receiver and end approximately 2 inches from muzzle for mounting sight base or barrel band. A skip in one flute can be incorporated at 7.200 inches from receiver to mount scope base. From Lilja Precision Barrels Fluted Barrels Fluting barrels for both competitive target and hunting rifles is quite popular. There are two advantages to using a fluted barrel. Improved accuracy is one advantage because of increased barrel stiffness. (...) Another advantage to fluting is the increased cooling rate of the barrel because of the greater amount of surface area exposed to the air. Look at the radiator in your car. Is it high mass and low surface area? Of course not, just the opposite. It is a device to conduct heat away from itself. It is relative low mass metal with great surface area. If a higher mass would help then radiators would be made of iron. Look also at utility poles made of steel. They are not round as that is not the stiffest shape. They are octagon, which is much like fluting in shape. This contributes to the stiffness of the pole. There are still people that think iron ships cannot float and planes cannot fly. Go figure. These companies are misrepresenting physics. The radiator in your car is not a device to store heat; it is a device to transfer heat. The transfer goes from the producer (the ICM) to a liquid (water) to the radiator. Radiators are not iron because aluminum has a higher thermal conductivity and also lends itself to the manufacture of radiators fins and tubes. The other myths I addressed in my previous post. I recommend these books for you: Foundations of Materials For Science And Engineering Smith 2nd Ed. Mac Graw Hill Thermodynamics and Heat Transfer Yunus A.Cengel Mac Graw Hill [b]If barrel weight is not a factor, fluting a barrel is nothing more than a cosmetic upgrade.[/b] -The post fluted barrel is not stronger than the pre-fluted barrel. -The post fluted barrel does not have less whip and associated harmonics compared to the pre-fluted barrel. |
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A fluted heavy bbl. is stronger than a pencil (non-fluted, of course), but weaker than an unfluted heavy bbl. of the same dimensions, where the basic difference in strength can be owed to the greater cross-sectional area of the non-fluted one. The only way for a fluted bbl. to be able to match the strength of the non-fluted one is for both to have identical cross-sectional area. Of course, the geometry caused by the fluting also adds some wrinkles into the comparison. |
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