Fluted barrels?

Re: Fluted barrels?

Fluted barrels also cool faster. Necessary, no. But it does shave off some weight from the front of the rifle. How much weight depends on barrel length and how deep the flutes are.

My 7WSM has a 28" deep fluted MTU contour barrel, lol yah its a pig. I imagine on mine it took off a clean pound if not more. My rifle weights 18lbs IIRC, sure is better than 19lbs
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Re: Fluted barrels?

Advantages alreayd stated, weight savings and cooling, and they look sharp. The disadvantages to fluting only tend to show up if you are fluting a barrel that happens to be a poor candidate 'after the fact' and not during the original manufacturing process. Basically its like this, you have a barrel of X contour and weight. Barrel thickness is a certain number all the way across. You have the barrel turned down to your desired contour, chambered, crowned/threaded what have you. You take your barrel, screw it into your rifle, pop off a few hundred rounds and decide its a little heavy and you want to flute it. Now you flute your barrel, you are removing even more metal, reducing the barrel thickness in the places that are fluted. As a result, your barrel weighs less and is now less rigid than a unfluted barrel of equal contour and thus becomes a little more temperamental to things like heating or harmonics. Yes, fluting cools a barrel faster but theres the caveat, your fluted barrel has less material than an unfluted barrel of equal contour/size and will probably heat up faster than the unfluted barrel. Ideally, you want the barrel fluted from a larger dia. contour and shaved down to the contour you actually want, this way you end up with a fluted barrel that has the same amount of weight, metal, and barrel thickness as the barrel you originally wanted to get fluted. They weigh the same now but the one with the fluting has the advantage of faster cooling without the drawback of having reduced barrel wall thickness.

This really gets exacerbated in extreme cases and probably would not be an issue if you were fluting a bull barrel; if you were trying to remove metal from say a lightweight or pencil barrel you would run into some possibly dangerous issues of having far too thin barrel thickness at the flutes.
 
Re: Fluted barrels?

I have a 22" Varmint contoured Benchmark barrel blank. It's a 6.5mm 3 groove. We weighed it before fluting and after. I fluted it with 12 flutes and it removed .75 lb. If you want to see what your barrel would end up weighing try visiting Pac Nor's website. They have a barrel weight calculator where you can enter the number of flutes, barrel contour, length...etc and it will tell you the weight.
 
Re: Fluted barrels?

I see some people claim that a fluted barrel is more rigid than an unfluted barrel. That's not entirely true. The fluted barrel should be more rigid than a barrel of identical weight since the fluted barrel is of a heavier contour. However, if you took 2 barrels of identical contours and fluted one of them, the unfluted barrel will be more rigid as it still contains more mass.
 
Re: Fluted barrels?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pepperbelly</div><div class="ubbcode-body"> What are the disadvantages of a fluted barrel?</div></div>

90% eye candy, 10% function

I've had and still have both. Cant really tell any difference weight or accuracy. 6 deep flutes may shave off maybe 1 Lb on some rifles but it realy just boils down to being eye candy.
 
Re: Fluted barrels?

Brad from ND,
I'm not trying to start an argument but I'm interested in the math/thinking behind your statement. I have always considered a fluted barrel in terms of a bunch of "I-beams" joined together, and therefore less likely to flex than a solid bar.. or barrel in this case. I've never explored the math.. it's just a gut-feel opinion.

any thoughts on that?

RJ
 
Re: Fluted barrels?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">advantage: chicks dig 'em.</div></div>

What better reason to have them............flute on
 
Re: Fluted barrels?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">advantage: chicks dig 'em.
disadvantage: cost money.</div></div>

yeah.. screw the math.. that's the correct answer!

RJ
 
Re: Fluted barrels?

Richardj, I can see your thinking on that, but an I-beam has a top to the "I" to help control flex. A flute does not. I personally don't think anyone could ever tell a difference between a fluted barrel and an unfluted barrel accuracy wise, as long as it was properly installed. I did get my original information straight from a barrel manufacturer, I just can't remember which one.

Oh, and I like my barrels fluted as well!
 
Re: Fluted barrels?

I did 6 HEAVY flutes on mine. Took off 1LB 2OZ. Used a #6 involute gear cutter .190 deep with a 90 degree spiral. Ask Mr. Roscoe how deep it looks. I think William said when a guy at his shop looked at it, "He gave it a double take and said HOLY CRAP". Shot it the other day and it's still a laser.

Balances like a dream now.

Trilogymac
 
Re: Fluted barrels?

I'll see if I can get anytime on our ANSYS mechanical software at work and put the problem to something that can answer the question..


What flute dimensions should I use?
Barrel diameter & profile
Barrel length?


RJ
 
Re: Fluted barrels?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: richardj</div><div class="ubbcode-body">Brad from ND,
I'm not trying to start an argument but I'm interested in the math/thinking behind your statement. I have always considered a fluted barrel in terms of a bunch of "I-beams" joined together, and therefore less likely to flex than a solid bar.. or barrel in this case. I've never explored the math.. it's just a gut-feel opinion.

any thoughts on that?

RJ </div></div>

I'm not Brad and cant give you the math but I'll give the explaination a shot.
Lets say your I beam started life out as a solid piece 6" wide and 10' long. We then put it on a giant mill and milled out material to turn it into an I beam. Think about it, would it be more rigid in its original form or as an I beam? Remember, we're not talking about stamping steel here, we're talking about removing material from solid steel. there's a big difference. Anytime you remove material from steel, you weaken it. If it were a sheet of steel that we "stamped" flutes into, it may make it more rigid but that is NOT what we're doing when we mill flutes into a barrel. For a fluted barrel and a non fluted barrel of the same caliber to be of the same rigidity (is that a word?) the fluted will have to be a larger O.D. or different density. Hope I made sense.

okie

PS. JFYI, I like flutes
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Re: Fluted barrels?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pepperbelly</div><div class="ubbcode-body"> What are the disadvantages of a fluted barrel?</div></div>

90% eye candy, 10% function

I've had and still have both. Cant really tell any difference weight or accuracy. 6 deep flutes may shave off maybe 1 Lb on some rifles but it realy just boils down to being eye candy. </div></div>

That 10% may be 8% too much?

That being said....Wicked cool....
 
Re: Fluted barrels?

As far as the cost goes, I figured this is worth mentioning. When you go with a fluted barrel, the cost of the fluting ($110-$130) isnt the only thing you pay, most smiths charge $35-45 more when they use a fluted barrel for your build to index the flutes. So going with a fluted barrel can add $145-$175 to the cost of your build.
 
Re: Fluted barrels?

RichardJ, this is from Lilja's website:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Improved accuracy is one advantage because of increased barrel stiffness. If we compare a fluted barrel to one that is not fluted, both weighing the same, the fluted barrel is stiffer. This is because the fluted barrel will be of a larger diameter than the unfluted barrel of the same weight and length. Increasing the diameter of a barrel greatly increases its rigidity.</div></div>


Pretty good explanation of why a fluted barrel is stiffer than an unfluted barrel of the same weight, but it's not as stiff as an unfluted barrel of the same diameter.
 
Re: Fluted barrels?

Wow now is the time I wish I had an engineering degree.... I actually read an article about this a while ago that had the mathematics to back it up. Two barrels identical lenght and O.D. one fluted andthe other not, fluted will cool faster and origanal will be more rigid. All fluting does is increase the surface area and not increase in rigidity.

The math and diagrams that I read were for regular round flutes not the wide square flutes like the one on a LTR.

Edit the drool factor is not calculated in on an unfluted stick.
 
Re: Fluted barrels?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: snufulufugus</div><div class="ubbcode-body">Wow now is the time I wish I had an engineering degree.... I actually read an article about this a while ago that had the mathematics to back it up. Two barrels identical lenght and O.D. one fluted andthe other not, fluted will cool faster and origanal will be more rigid. All fluting does is increase the surface area and not increase in rigidity.

The math and diagrams that I read were for regular round flutes not the wide square flutes like the one on a LTR.

Edit the drool factor is not calculated in on an unfluted stick. </div></div>

did your article mention that a fluted barrel will also heat up faster than a non-fluted barrel of the same dimensions?

i would love to see some proof that a fluted barrel makes a practical difference due to heat dissipation on a bolt action rifle. until i see that proof, i'm not buying into it. in my opinion, looks and weight savings (in that order) are the only practical reasons for a fluted barrel.
 
Re: Fluted barrels?

Yeah, I've wondered the same. I would think though that the heating up faster would'nt make any more of a "practical difference" than the cooling off faster would, or visa versa. Fact is (talking about barrels with the same O.D.) the flutes should slow the heating also, question is, how much would they counter the fact that lack of mass would speed it up? If we're talking about barrels of the same weight though, there is no lack of mass so wouldn't the fluted gain an advantage in cooling because of increased surface area?

okie
 
Re: Fluted barrels?

Sorry guys. I just don't buy into the fluting. I'm with wnroscoe. 90% of it is looks. There may be some benefits, but I'll save the extra money and put it towards ammo. I bet 175 bucks of ammo would make me a better shooter than 175 bucks worth of flutes.

If one pound off your rifle is worth the cash to you, consider buying a gym membership. It will be better for you in the long run and you wont notice the extra pound that you shaved off the barrel after a month at the gym. If its a balance issue, then someone messed up by putting too heavy of a contour on your rifle. Fluting then becomes a bandaid.

Or get the flutes. Its your rifle.
 
Re: Fluted barrels?

Do Not Flute.

I had a fluted barrel once (Robar QR2). The rifle fell when I let it lean against an object and started messing with my gear (mea culpa). It landed just right on one of the flutes, chipped the edge and changed the accuracy. I re-zeroed and it shot fine but I will not tolerate a "fragile" rifle. If a few ounces will make that much of a difference in weight...hit the gym.
 
Re: Fluted barrels?

I personally dont care if a barrel's fluted or not. There is and has been for years many fluted barrels in the field, thats the first time I've heard them described as "fragile".

Speaking realistically, when you can shave a full pound off just one area of one piece of gear, its sugnificant whether your a gym member or not. In developement and testing of any gear, ounces are sugnificant. If that were'nt the case, we could all just hit the gym and carry 500 rnds and a Barrett .50 all the time
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okie
 
Re: Fluted barrels?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: George Mac</div><div class="ubbcode-body">Do Not Flute.

I had a fluted barrel once (Robar QR2). The rifle fell when I let it lean against an object and started messing with my gear (mea culpa). It landed just right on one of the flutes, chipped the edge and changed the accuracy. I re-zeroed and it shot fine but I will not tolerate a "fragile" rifle. If a few ounces will make that much of a difference in weight...hit the gym. </div></div>

are you saying it changed the accuracy or just changed the poi? if it dropped hard enough to chip a flute, i have a feeling it would have changed the poi with a non-fluted barrel also.

fluting barrel creating a fragile rifle, that's a new one.
 
Re: Fluted barrels?

The only advantage of a fluted barrel is weight. If you take two barrels that are 1.25 strait blanks and flute one, it will obviously weigh less. The construction is not of an I-beam type so you are comparing apples ot oranges. If you take a cross section of the barrel it would not be an "I" shape but more of an upside down "T" shape. Now imagine that he horizontal line is a base structure and the vertical line is the support. In a solid barrel, that support is simply larger; thus it has more rigidity. It is true that the fluted barrel will cool faster but that is because there is less mass to retain the heat. The increased surface area is not much gained in comarision to the mass and I would venture to say has almost no effect on cooling in this arena. It is also true that a fluted barrel will heat up faster since it is of less mass. The solid barrel will take longer to heat up, but will also retain the heat longer since there is more mass. I belive Harold Vaughn in his book addressed this issue and said there were some harmonic problems with fluted barrels. However, I have loaned out the book and do not recall fully.

In the end, it ends up coming to personal preference. A shooter takes all aspects of his shooting game and decides himself what he thinks is best for his situation. (weight, accuracy, how many rounds will be fired and at what, etc) Its all variables with give and take at both ends.
 
Re: Fluted barrels?

XLR, I certainly agree that construction is nothing like an I beam and I tried to convey that in my post on same. Dosn't matter what the shape, if you're removing metal, you're making it weaker or in this case, less rigid....period. Like I said before, we're not stamping out shapes here, we're removing metal. Maybe you confused my post with someone else or maybe my explaination wasn't very good. I respectfully disagree on the cooling though. Seems to be well proven that increasing surface area increases cooling. Vanes are just exagerated flutes. The vanes on the head of an aircooled engine do nothing more than increase surface area and they have worked pretty good for quite a few years now. Knock a few of the vanes off a two stroke dirt bike and see how long it takes ot to run away with you because of overheating, dont ask me how I know this
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Ya know, this sure would be a good reason for a few of you "moneyed folks" to buy a bunch of new rifles with varying barrels and do some testing, then we could stop all this speculation. Great discussion, good points being made and everyone is still acting like a grown up, amazing.
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okie
 
Re: Fluted barrels?

Sorry okiefired, I wasn't directing that post directly to you, you just must have been the one I was on when I responded. I did some quick math to find out just how much surface area is gained by adding flutes. The "barrel" I used was a 1.25 strait blank that is 24 inches long (just to keep things simple) Flutes measured would be .375 wide cut to .1875 deep. (pretty healthy flutes) and there would be a total of 6 flutes. I took the surface area of the barrel not including the ends: 2pi.625(24)=94.2 in^2. Then I calculated the area of the flutes: ((2pi.1875^2+2pi.1875(20))/2)*6=71.31". Then I calculated the area of the material removed. First I found the circumference of the barrel: pi(1.25)=3.925". Since there were 6 flutes .375 wide: 6*.375=2.25. Therefore 2.25/3.925=57.3% removed from a 20" area. Take the area of 20" of barrel: 2pi.625(20)=78.5*.573=44.98" removed. Therefore, total area of the barrel minus area removed plus added flute area equals new total surface area 94.2-44.98+71.31=120.53"^2. 120.53/94.2=1.2795 Therefore total area of the barrel increses by 27.95%.

I must admit that that was more than I thought it would add. Now someone just needs to figure out how much that increase in surface would affect the total mass of the barrel for cooling.
 
Re: Fluted barrels?

I think if weight is a big issue for a hunting rifle you could attend to the following

1) rebarrel the rifle with a shorter barrel OR get your barrel chopped and re-muzzled
2) flute your barrel
3) hit the gym
4) learn proper rifle form and how to utilise a sling to help using different muscle groups... for example a sling can help you hold your rifle by using your shoulders, lats and triceps simply by wrapping the sling around your elbow and pulling back with your shoulder.
 
Re: Fluted barrels?

Great post XLR, you lost me at 2pi though
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. I'm surprised also that surface area is increased that much, I think that much could aid in cooling. How much.......who knows? Ahhh what the hell, I just like the way they look.

okie
 
Re: Fluted barrels?

Anybody else notice fluted barrels showing more scope mirage than unfluted? When shooting a fluted #7 barrel next to a unfluted #7 I notice mirage effects earlier. Scopes and mounting heights are different so I am never certain it's the flutes causing it. TJR
 
Re: Fluted barrels?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bluejazz</div><div class="ubbcode-body">
IMG_1093.jpg

I like the look of these staggered flutes. Not sure about function, but sure look good. No sense in shooting an ugly gun. </div></div>


thats hot. id love to see the rest of that rifle