Does fluting affect barrel accuracy?

[cowboy717]

Im talking to a smith to build a rifle. Im wanting a fluted barrel but hes trying to talk me out if it saying they are less accurate? Is there any truth to this? Ive seen many fluted barrels on this site that shoot amazing. And i have a vtr in 308 that shoots very well too.

 

[c_bass16]

Im talking to a smith to build a rifle. Im wanting a fluted barrel but hes trying to talk me out if it saying they are less accurate? Is there any truth to this? Ive seen many fluted barrels on this site that shoot amazing. And i have a vtr in 308 that shoots very well too.

According to Shilen...yes.
They won't do it from the shop and it will void the warranty if you have your smith do it. I'm not an expert and have no equipment/funds to verify anything like this...but I'll take their word for it.
In fact, I am having my .243WSSM AR rebarreled with a Shilen Select Match, AND I bought 2 more for bolt guns...that I planned to flute, and have since decided not to.

I'm young and tough and could care less about weight, I was doing it more for the look, and I don't care enough about the look to risk messing with the accuracy.

 

[Joe King]

Copied from FAQ on Lilja's web site

Q: Does fluting cause stress in a barrel?

A: We've been asked if machining flutes into a rifle barrel causes stress in the steel. The short answer is no, it does not. There are some operations in the manufacture of a rifle barrel that can cause stress to develop in the steel, but fluting is not one of them. To the contrary, fluting can and will relieve stress if it is already present. The same is true of any outside machining work performed on a barrel.
The type of stress that can exist in a barrel is called compressive stress. Under normal conditions the stress could form from two processes. When steel is manufactured, the round shape is formed through a rolling operation in the steel mill. This forming can be performed either hot or cold. Cold rolling generates a great deal of internal stress in the steel. Usually, with steel used for rifle barrels, this stress is relieved by heating the steel to just below its transformation or critical temperature. We have the steel mill that makes our steel do this as their very last operation, ensuring us that the steel is stress free when we receive it.
Secondly, stress can be formed in a rifle barrel during a cold forming operation, such as button rifling. Since no material is removed from the barrel when the rifling is formed, rather it is displaced, it causes compressive stress in the steel. If this stress is not removed, through a heat treating operation, it will remain in the steel where it can cause other problems. Any subsequent machining operations, such as turning the outside diameter of the barrel, will allow some of those stresses to come out. The result can be an opening of the inside diameter of the barrel, more so towards the muzzle where more material is machined away. It can and probably will also cause the barrel to warp. And if these aren't enough, the temporary heating and cooling of the barrel that occurs during normal firing will also let the stress come out by warping the barrel. Poor accuracy is the result.
Although a barrel would not normally be welded on, this can also cause stresses to form in steel. At times though, gunsmiths will heat barrels to sweat-on barrel bands and sites. Too much heat can cause some problems as well.
But, the fact remains that normal machining operations, such as outside turning, fluting, drilling and tapping site holes, etc. do not cause or introduce stress. They can and do allow residual stresses to come out of the steel though.
We flute about 50 rifle barrels per month and have never had a problem with our barrels related to fluting.

 

[Korhil78]

Guys on here have guns that shoot half MOA past 1k and their barrels are fluted. I don't think it's an issue.

 

[Hunter2678]

Phewww I was worried there for a second...

 

[Aldon]

It is like the lottery.

It can and does occasionally effect accuracy.

Two major barrel makers have statements to that affect. One is more specific that the actual fluting does not cause it but the relieving of stresses can eventually result in warping etc...

So it really comes down to whether you are a risk taker or risk averse.

Make an informed decision and be willing to accept what you get.

As noted, there are many who have accurate fluted barrels.

I have a rifle that is indicative of the Lilja explanation.

I really like the look of fluting more than I care about the minimal weight reduction. i am particularly fond of the interupted fluting. I may even choose to go this way in the future.

However if I do, there is a real risk, albeit perhaps not a significant one, that I will end up with another dog. In the end, I am out the cost of the barrel and the smith work along with the time without the rifle. As such, that is the information I have to weigh should I want to go the route of interupted fluting in the future.

In short, the mere fact that there are those that have accurate fluted barrels does not wholly negate the information from Shilen and Lilja.

 

[Outlaw6.0]

This is an interesting topic. One which much folklore & hypermythology has been created (I just made that word up).

The major differences you will see in whether or not fluting will effect a barrel is (in my sheltered world) a direct reflection of what type of rifling the barrel wears.

I have several Shilen barrels & they shoot awesome. Shilen (among others) are button rifled barrel. The material is displaced by the button, not removed like a cut rifled barrel. So imagine a few spiral pressure ridges (for lack of a better term) running down your barrel. Now, start to remove material from the other side of the barrel... See how that COULD create a problem? Think about the barrel density as the flutes (straight) pass over the area where the button has displaced the material during the creation of the rifling. Inconsistencies abound! At least from a plausability stand point.... Now there is going to be the gent that says "Hey! My Savage barrel is button rifled & fluted too! So phuey on you!"... take a a long hard look at your fluted Savage barrel (I have 2 & both shoot well). the barrel diameter is larger than a sporter & the flutes are FAR shallower than an aftermarket fluted bbl. I would imagine (I do that often lol) there is a very good reason for that procedure.


A cut rifled barrel having the material removed rather than displaced should not incur these issues as there is very little material "compaction" from the rifling process.

Clear as mud?

Fluting a barrel seems to be the modern version of Truth or Dare....

Button Rifled Barrels:
Can you? Of course
Will is hurt it? Plausable.

Cut Rifled Barrels:
Can you? Of Course
Will it hurt? Probably not.

PS- This is solely my opinion & a good bit of experience with Gunsmiths & use of both barrel types. This is not an end all for the discussion, merely my .002 - Enjoy

 

[rscott5028]

I don't know about all the mumbo jumbo theory.

But, you're pretty much ok if you find a maker that'll flute their own barrel and honor the warranty.

Occasionally, all makers turn out a lemon whether it's fluted or not.

-- richard

 

[Boss Hoss]

No --- if fluting is done correctly it will not have a negative effect on the tube. Many world records have been set with fluted tubes in the BR game. Almost all of my rifles have fluted barrels and that includes the competition ones as well. If anyone tells you that the act of fluting itself will decrease the accuracy potential of a barrel by the act itself you need to find a good Smith that knows what he or she is doing. Mine does so I do not have to worry.

 

[7stw]

To my best understanding of the reason for for fluting, other than the aesthetics, is, that it is two fold. It stiffens the barrel, which in turn, should enhance accuracy, and secondly, it adds surface area, which aids in cooling, both of which to me, seem to have an affect on accuracy. From a pure mechanical standpoint, I would say yes, it does add to the accuracy . It seems to me, that the fluted barrels that I have shot, seem to be easier to " get to shoot" versus non fluted. ( ALL else being equal).

 

[RTK]

Actually, if two identical sized/shaped/weight barrels where one was fluted vs the other that has not been fluted, the non fluted barrel will be stiffer than the fluted one, but the fluted one will be lighter.
The increased cooling d/t increased surface area is negligible as I have been told

 

[shortpants]

Commen sense tells you that if it cools faster it also heats up faster. The stiffness argument was answered above. Word games. 2 barrels of the same weight one fluted one not, the fluted will be stiffer. It will also have to be a heavier contour to end up at the same weight.

 

[calling4life]

For me
Button rifled= don't flute, and actually for me right now it = don't buy. For reasons previously stated.

Cut rifled= go ahead, my rock is fluted, I wanted the bit of weight savings.

With the quality cut rifled barrels, I just don't have a reason to go button rifled, especially if I'm trying to justify it because I may save $50...

As with anything, if the person doing the fluting tries to stretch the limits, or makes an error etc... then you may get adverse affects. But this is the same with chambering and cleaning and bedding bla bla bla

I'll personally get fluted from the manufacturer as well, this mitigates risk.

 

[jehu]

Commen sense tells you that if it cools faster it also heats up faster. The stiffness argument was answered above. Word games. 2 barrels of the same weight one fluted one not, the fluted will be stiffer. It will also have to be a heavier contour to end up at the same weight.

My Sako 85 Finnlite 22-250 with pencil fluted barrel heats up very quickly and starts walking groups to the right as it gets hotter.