To flute or not to

[TackDriv3r]

I am in the process of making the list for my new build for GA Precision to build me a 6.5 Creedmoor. It will be the Crusader with a 26 inch barrel and 1:8 twist. Fluting will help reduce weight and have not made a decision. Will fluting reduce stiffness and rigidity and reduce accuracy at long range? Opinions is appreciated

 

[LHSmith]

Anytime you remove metal from the barrel you reduce rigidity. Accuracy can suffer from the fluting process if done incorrectly by inducing stress in the barrel. Cut rifled barrels are less affected by fluting.

 

[rpierce]

As long as its done correctly you won't have issues. I put fluted barrels on 90% of the rifles I build for customers and I have gotten 1/4 moa or better groups from every customer. The exception to that is the 3 barrels that were duds. Not a bad % rate considering Ive been doing it for 7 years now.

 

[TackDriv3r]

Thanks guys for the feedback, I have decided not to flute it.

 

[loud_noise]

I have a 30" fluted Med Palma profile and have zero issues hitting V's and the occasional X in Palma style comp...when I do the right thing. Done correctly it will give you no issues

 

[mgunderson]

Always interesting to me to see if the groove is "top center" or if the grooves are spaced to each side. Not sure if that makes sense.

 

[JRS]

If you are going to use a fluted barrel, let the barrel maker perform that operation. They contour, flute, then lap the barrel. You also have the warranty from the maker. The late Skip Otto held the NBRSA 200 yard 5 shot group record at one time, using one of his fluted barrels.

 

[Mr.Knowit all]

I agree with LHSmith- Accuracy International did a study on this and found that fluting the barrel could hurt accuracy and they stopped fluting all of their barrels. I read the study and decided that I would not flute any of mine. It was very interesting- basically the fluted barrel did not distribute heat as evenly as the none-fluted barrel and it caused a POI shift. AI is top of the line, maybe even the best (if there is such a thing) so if they change something I tend to give it a look.

 

[JRS]

Bartlein Barrels:
"Fluting will remove steel from the barrel making the barrel lighter and henceforth help make the rifle lighter overall as well. It will give the barrel more surface area which can help it cool a little faster".

Krieger Barrels:
" Flutes aid in cooling a barrel by exposing more surface area to the outside air. Flutes can also increase the rigidity to weight ratio of the barrel, thereby reducing barrel vibration and whip over a barrel of the same weight un-fluted".

Lilja Barrels:
"There are two advantages to using a fluted barrel. Improved accuracy 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 an un-fluted barrel of the same weight and length. Increasing the diameter of the barrel greatly increases its rigidity. Another advantage is the increased cooling rate of the barrel because of the greater amount of surface area exposed to the air".

So…. WoodchuckWhacker, if you have experience and knowledge that our barrel makers do not have, feel free to entertain us and share that knowledge.

 

[jpmimproved]

I personally have never seen significant differences in fluted vs nonfluted, but just to play devil's advocate:


Lilja - "If the barrel is fluted a maximum heavy varmint blank is usually used and for good reason. As we saw above, the larger the diameter, the stiffer it is going to be. Using a heavy varmint blank then gives us the maximum diameter allowed. Fluting a barrel removes weight, up to one pound or so depending on flute size. It also lowers a barrel’s moment of inertia value but not by very much. Some have the mistaken idea that fluting alone increases the stiffness of a barrel. This is not true. The fluted barrel of a given weight and length will be stiffer than an unfluted barrel of the same weight. The fluted barrel will not be stiffer than the same taper and length barrel that is not fluted though."

Shilen -
"What about "fluting" a barrel?
Fluting is a service we neither offer nor recommend. If you have a Shilen barrel fluted, the warranty is void. Fluting a barrel can induce unrecoverable stresses that will encourage warping when heated and can also swell the bore dimensions, causing loose spots in the bore. A solid (un-fluted) barrel is more rigid than a fluted barrel of equal diameter. A fluted barrel is more rigid than a solid barrel of equal weight. All rifle barrels flex when fired. Accuracy requires that they simply flex the same and return the same each time they are fired, hence the requirement for a pillar bedded action and free floating barrel. The unrecoverable stresses that fluting can induce will cause the barrel to flex differently or not return from the flexing without cooling down a major amount. This is usually longer than a shooter has to wait for the next shot. The claim of the flutes helping to wick heat away faster is true, but the benefit of the flutes is not recognizable in this regard until the barrel is already too hot"

I think really the take-away is that, like almost everything with shooting, every one has their own opinions.

 

[XTR]

If you have an F-TR rig with a barrel that's over .950 at 32" you can easily have over ¼ lb shaved off....

 

[JRS]

I personally have never seen significant differences in fluted vs nonfluted, but just to play devil's advocate:


Lilja - "If the barrel is fluted a maximum heavy varmint blank is usually used and for good reason. As we saw above, the larger the diameter, the stiffer it is going to be. Using a heavy varmint blank then gives us the maximum diameter allowed. Fluting a barrel removes weight, up to one pound or so depending on flute size. It also lowers a barrel’s moment of inertia value but not by very much. Some have the mistaken idea that fluting alone increases the stiffness of a barrel. This is not true. The fluted barrel of a given weight and length will be stiffer than an unfluted barrel of the same weight. The fluted barrel will not be stiffer than the same taper and length barrel that is not fluted though."

Shilen -
"What about "fluting" a barrel?
Fluting is a service we neither offer nor recommend. If you have a Shilen barrel fluted, the warranty is void. Fluting a barrel can induce unrecoverable stresses that will encourage warping when heated and can also swell the bore dimensions, causing loose spots in the bore. A solid (un-fluted) barrel is more rigid than a fluted barrel of equal diameter. A fluted barrel is more rigid than a solid barrel of equal weight. All rifle barrels flex when fired. Accuracy requires that they simply flex the same and return the same each time they are fired, hence the requirement for a pillar bedded action and free floating barrel. The unrecoverable stresses that fluting can induce will cause the barrel to flex differently or not return from the flexing without cooling down a major amount. This is usually longer than a shooter has to wait for the next shot. The claim of the flutes helping to wick heat away faster is true, but the benefit of the flutes is not recognizable in this regard until the barrel is already too hot"

I think really the take-away is that, like almost everything with shooting, every one has their own opinions.

"A fluted barrel is more rigid than a solid barrel of equal weight"

 

[dmoran]

If you have an F-TR rig with a barrel that's over .950 at 32" you can easily have over ¼ lb shaved off....

Are you sure of your input, at only a 1/4 lb reduction?
Reason asking, on barrels that I have fluted, 6-flutes 22" long each makes the barrel 1-lb lighter.
Donovan

 

[XTR]

Are you sure of your input, at only a 1/4 lb reduction?
Reason asking, on barrels that I have fluted, 6-flutes 22" long each makes the barrel 1-lb lighter.
Donovan

I had Kampfeld flute that one last yr with a weight reduction target, not a fluting depth/length target. I don't recall what we exactly what we finally took off of it or the depth of the flutes.

The rifle was about 4 oz over weight before it was fluted, and I think it dropped a bit over 8 oz or so with the flutes. It's comfortably under now. I think it will makes weight if I have to switch scopes from the Comp (only have the one) to an NXS (have more), but I haven't checked.

 

[jpmimproved]

"A fluted barrel is more rigid than a solid barrel of equal weight"

Yup. You can increase the contour and still keep the same weight and have more rigidity. However, if contour stays the same, fluting does not improve rigidity.

 

[dreever]

GA Precisions top of the line Hospitaller has a fluted barrel and accuracy is stellar.

Danny

 

[PAshooter20BR]

kampfeld custom has done all my barrel fluting for me. Straight or spiral all my bartliens are tack drivers. If I recall years ago on another forum a gentlemen had a custom 308 that was a fantastic shooter. He sent his barrel to kamfeld to have it fluted. When it returned it still shot the same load exactly the same and there was no change in accuracy. It was a good read and neat experiment...it was part of a posting on barrel fluting just like this one.

 

[thekubiaks]

not to flute.....

 

[CTK]

Looks cool but sounds like could buy trouble.

 

[flatlander]

I've built a couple of 7mm Rem Mags with 10-fluted Kriegers that shoot really great groups for their owners - and they look neat, which I've always thought was one of the reasons people really wanted the flutes in the first place.

OTOH, I ordered in a factory fluted Krieger 6.5mm blank in medium Palma contour for another customer several years ago, then wound up buying it back from him when he ran into $$ problems. I chambered it in 6.5x47, fitted it to a trued M700 in a laminated wood copy of the McM A5, and proceeded to try to find a good load for it. That SOB turned out to be one of the pickiest bbls I've ever chambered - I found exactly one load that shot acceptably well out of it.

Right now, I've got a Howa long action out in the shop that I fitted a Krieger in 280 AI for. The blank was ordered in as a #5 sporter, but when I opened the box, it turned out to be a #6 sporter, which is considerably heavier than I wanted. I've been thinking about sending it out to one of the shops I trust that specializes in fluting bbls & bolts, and having them do the 10 flute pattern that Krieger offers in an effort to reduce weight - may go ahead with the plan, since I doubt seriously that I'll ever be able to sell it as-is. Should do some shooting with it before to establish an accuracy baseline, then I'd have an idea whether the fluting hurts accuracy or not.