Effects of Barrel Fluting on Accuracy

[chkunz]

As T-REX stated shooting prone. The way I shoot I might not be able to notice a difference off the bench in fluted or not. I do a little shooting setting and standing. The best thing for the OP [ or anyone ] can do is go to the fitness center 2 or 3 times a week to fight old age.
Do they flute a barrel and turn the OD before it's bored ?

my 2 cents.

Link

I agree with the advantage of going to the gym. Walking and light weight training helps me a lot. If you decide to try it be careful and work up very slow to give the body a chance to respond without hurting something.

 

[Joe R]

Clyde,
I don't know how old you are, but I think its great that you want to continue to stay in the game. I also commend you for the ambition to find ways to uncover new ground and sharing it with us. Please keep us informed on your results, after all we may benefit from your curiosity since none of us are getting younger.

Kindest regards,

Joe

 

[ERGJ]

As T-REX stated shooting prone. The way I shoot I might not be able to notice a difference off the bench in fluted or not. I do a little shooting setting and standing. The best thing for the OP [ or anyone ] can do is go to the fitness center 2 or 3 times a week to fight old age.
Do they flute a barrel and turn the OD before it's bored ?

my 2 cents.

Link

I agree with the advantage of going to the gym. Walking and light weight training helps me a lot. If you decide to try it be careful and work up very slow to give the body a chance to respond without hurting something.

Very good advice! If no problems to stop you from weight training, then go at it; slowly at first, and harder after a while. Big difference in my abilities to shoot a handgun. A little over a year ago I switched from a Glock 19, 9mm to a Glock 32, 357 Sig. It took me about six weeks of practice before I would carry it, as I was not as accurate with the 357 Sig round as with the 9mm. Since then I joined a gym and started working out. I now really push the weights to gain strength and muscle in my arms, chest, shoulders, back, and core. I do hurt for a day or two afterwards. However, I am now as accurate with the 357 Sig round as I was with the 9mm round. I now am getting the Glock 20, 10 mm, just for giggles, as I am going to use it with a Lone Wolf 9x25 Dillon barrel. All because of some heavy duty weight training. It works, try it after your doctor's OK. By the way, I'm 75 and want to keep shooting as long as I can be mentally and physically fit. Go for it.

 

[MOShooter]

This is from Precision Rifle Blog.com. It is rather lengthy but it good info.

"There are some people in the shooting community that do believe fluting affects a barrel’s accuracy in a negative way. In fact, Shilen Barrels refuses to flute their barrels. Here is what they say on the topic:

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.

Several months ago, I asked Shilen for any data they have to support these claims, but they never responded. So this smells like it could just be a strong opinion and theory, and may not be backed by any empirical data they’ve gathered.

But an article written by Tom Beckstrand in the 2013 edition of SNIPER magazine summarizes some tests that Accuracy International performed to determine whether fluting a barrel affected accuracy. Here is an excerpt from that article:

One design change that resulted from AI’s exhaustive accuracy testing and development of the PSR [Precision Sniper Rifle] is the removal of flutes from the barrels. Engineers at AI decided to isolate the barrel flutes to see what impact they had on accuracy. The engineers attached a laser to the rifle’s receiver, another to the barrel, and a third to the scope. All three dots were zeroed at the same point, then they started shooting the rifle. They discovered that, no matter which fluted barrel they used, the dots would diverge as the barrel heated. The dots from the devices mounted to the scope and the receiver would stay in place, but the barrel’s device would manifest a point-of-impact (POI) shift. The POI shift from the warming barrel greatly diminished when they used barrels without flutes.

Engineers determined that the flutes never heated evenly, causing the POI shift. I hope the results of this test gain wide circulation through the sniper and long-range shooting communities to help eliminate some of the ignorance that surrounds the perceived advantages of barrel flutes. Flutes are great for shaving weight, but this is the first test I’ve heard that provided empirical data detailing what happens when the barrel is fluted. This should be the death of the “they cool a barrel faster, so they’re more accurate” argument, listed among flutes’ virtues. Our goal is and should always be to mitigate the effects of heat; fluting exacerbates it."

 

[chkunz]

This is from Precision Rifle Blog.com. It is rather lengthy but it good info.

"There are some people in the shooting community that do believe fluting affects a barrel’s accuracy in a negative way. In fact, Shilen Barrels refuses to flute their barrels. Here is what they say on the topic:

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.

Several months ago, I asked Shilen for any data they have to support these claims, but they never responded. So this smells like it could just be a strong opinion and theory, and may not be backed by any empirical data they’ve gathered.

But an article written by Tom Beckstrand in the 2013 edition of SNIPER magazine summarizes some tests that Accuracy International performed to determine whether fluting a barrel affected accuracy. Here is an excerpt from that article:

One design change that resulted from AI’s exhaustive accuracy testing and development of the PSR [Precision Sniper Rifle] is the removal of flutes from the barrels. Engineers at AI decided to isolate the barrel flutes to see what impact they had on accuracy. The engineers attached a laser to the rifle’s receiver, another to the barrel, and a third to the scope. All three dots were zeroed at the same point, then they started shooting the rifle. They discovered that, no matter which fluted barrel they used, the dots would diverge as the barrel heated. The dots from the devices mounted to the scope and the receiver would stay in place, but the barrel’s device would manifest a point-of-impact (POI) shift. The POI shift from the warming barrel greatly diminished when they used barrels without flutes.

Engineers determined that the flutes never heated evenly, causing the POI shift. I hope the results of this test gain wide circulation through the sniper and long-range shooting communities to help eliminate some of the ignorance that surrounds the perceived advantages of barrel flutes. Flutes are great for shaving weight, but this is the first test I’ve heard that provided empirical data detailing what happens when the barrel is fluted. This should be the death of the “they cool a barrel faster, so they’re more accurate” argument, listed among flutes’ virtues. Our goal is and should always be to mitigate the effects of heat; fluting exacerbates it."

This is good info but I wish they would have given some indication as to what it is worth on the target. The conventional mid range prone slow fire target is big so I have some accuracy budget I am willing to give up for the weight trade off if I knew what I was giving up. But so far it can not be much since this barrel shoots very well. Also it would be good to know if reducing the barrel weight by the same amount as fluting would be a better way to go.

 

[chkunz]

Clyde,
I don't know how old you are, but I think its great that you want to continue to stay in the game. I also commend you for the ambition to find ways to uncover new ground and sharing it with us. Please keep us informed on your results, after all we may benefit from your curiosity since none of us are getting younger.

Kindest regards,

Joe

I am 72 and still shooting the M14 in XTC. I have also taken up mid range with the AR and long range with a tube gun in 260 Remington. I am sure I would have been out of the game several years ago without the gym.

 

[OldmanFCSA]

I have heard - read it on the Internet, so must be true - that fluting a button-rifled barrel will affect the bore size as fluting reduces internal stress as caused by the button-rifling process. I call "BULL" on this, but would like to hear/read from others with far more experience than I.

 

[LHSmith]

I have heard - read it on the Internet, so must be true - that fluting a button-rifled barrel will affect the bore size as fluting reduces internal stress as caused by the button-rifling process. I call "BULL" on this, but would like to hear/read from others with far more experience than I.

When the barrelmakers themselves make that claim, as virtually ALL of them do, I tend take take it as gospel. If any offer fluting, they will do it before final lapping.

 

[liliana]

thanks for info

 

[Uthink Uknow]

Skip Otto fluted every barrel he could touch. He is in the Benchrest Hall Of Fame.
Just saying.

 

[LHSmith]

^^^^^ Great point about a Bronze Jacket winner with 42 Precision Rifleman points. That leaves one to ponder if he handicapped himself with the fluted barrels preventing him from acquiring a Silver or Gold Jacket.

 

[CSM19Z5M]

I have read a few articles or threads on the subject and have come to the conclusion it isn't worth the trouble, cost or risk if we are talking about accuracy. None of my heavy barrel rifles are fluted. They all shoot much better than I do. Seems to me that there never would have been a reason to go to bull barrel or other heavy profiles in rifles if a slim sporter weight rifle shot just as well. Look at the tube gun super heavy barrel rifles some guys build. Don't see any noodle barrels on them do you? That's obviously being simplistic on my part and hardly scientific evidence, just an observation. I spent several years working as a machinist before becoming an engineer and have fluted many materials. I can tell you that there is quite a lot of force generated by the cutter head and machine in the feeding process that could, if the operator isn't careful, bend a slender profile such as a rifle barrel. So for now I guess, if you like the looks of a fluted barrel or the slight weight savings, go for it. If you think it cools the barrel a little quicker then by all means do it. But until someone has some controlled, quantifiable evidence one way or the other, I'm sticking with a heavy varmint or bull profile on my guns.

 

[chkunz]

I have read a few articles or threads on the subject and have come to the conclusion it isn't worth the trouble, cost or risk if we are talking about accuracy. None of my heavy barrel rifles are fluted. They all shoot much better than I do. Seems to me that there never would have been a reason to go to bull barrel or other heavy profiles in rifles if a slim sporter weight rifle shot just as well. Look at the tube gun super heavy barrel rifles some guys build. Don't see any noodle barrels on them do you? That's obviously being simplistic on my part and hardly scientific evidence, just an observation. I spent several years working as a machinist before becoming an engineer and have fluted many materials. I can tell you that there is quite a lot of force generated by the cutter head and machine in the feeding process that could, if the operator isn't careful, bend a slender profile such as a rifle barrel. So for now I guess, if you like the looks of a fluted barrel or the slight weight savings, go for it. If you think it cools the barrel a little quicker then by all means do it. But until someone has some controlled, quantifiable evidence one way or the other, I'm sticking with a heavy varmint or bull profile on my guns.

All well said but go back and read my original post and you will see that I did not try it to improve accuracy, I am only trying to reduce some weight and hoping for no reduction in accuracy. It may be that the better way to do this is with a different barrel contour but it looks like we have little data and a lot of openion. I am not being critical of you or anyone else and maybe we can all learn. When I shoot out the fluted barrel I will have one data point which is better than a guess maybe not much better but it is one data point. Take care.

 

[Raptor]

Accuracy International did a very extensive test on their rifles to see if fluting had an affect on accuracy. With all the testing that they did they said that there "Was" an affect on accuracy when they fluted the barrel. I read the article a year or so ago and found it very interesting. I am sure if you Google it you can find the info. Then you can form your own opinion. Hope this helps!!!

 

[JDMock]

Skip did flute all of his barrels, BUT he is NOT in the Hall of Fame. He was under the impression that fluting a barrel made it stiffer....which is impossible. Removing metal from a barrel will not make it stiffer. One thing that fluting will do is cause the bore to grow...i.e. get larger in diameter. Good shooting...James Mock

PS- I miss Skip very much and we had several good discussions (arguments) about BR shooting. Skip was very "set" in his ways and no intention of changing anything. He always used fluted barrels (even on his unlimited rifle). He was loyal to Panda actions, Shilen barrels and insisted on 15 twist. He made his own bullets and was a good shooter. He was the first to shoot a "zero" at 200 yds. in competition. Rest in peace Skip, James

 

[alf]

I used to shoot BR with Skip out in Porcupine, SD. No doubt, he had his opinion on any and all subjects....

My first Hunter BR gun, I sent my 308 Hart barrel, prior to chambering, to him to flute, so I could make weight with the old Weaver T-6. His flutes were not exactly photogenic, but I certainly never had an accuracy problem with that barrel throughout it's life.