Fluted vs. Not

[cory]

This discussion has probably happened multiple times on this forum, but honestly I didn't come across it in my search. And yes I was to lazy to search further back then the last several months. haha

So I've been working with Mark at Precision Firearms to build a 6.5 Gr AR around there 24" Neptune V (Five) Lilja upper 1:8 twist. I'm using a billet lower and a Magpul Prs stock to counter act the the heavier, longer upper. I intend to use this build to push the limits of the 6.5 Grendel in an AR platform.

I'm debating on using a fluted barrel as to save some weight.

Has anybody experienced any negative effects of a fluted barrel at longer ranges?

[bwaites]

Nope, no issues.

I shoot a fluted 28" out to 1000 yards.

You probably want to use a billet upper as well, if you want the best rigidity for max range.

[stokesrj]

None here either, I have several high quality fluted barrels and they all shoot really well.

[kamrr4437]

Mines fluted never had a problem

[cory]

Thanks! Between Mark and ya'll I believe I've been talked into it.

[kissmy300blkbrass]

What kind of flutter barrels you guys running?

[stokesrj]

I have a Satern and two Pacnors that are fluted.
Bob

[mongoosesnipe]

As long as the fluting is done during the barrel making process there is usually not a problem most of the problems I am aware of from fluting happen when people try to add fluting after the fact

[kamrr4437]

Mine are Satern.

[Mutt]

Fluting has very little if any effect on accuracy. There are several reasons (benefits) for fluting. The most comon and well known aspect is saving weight .... which you already know. Here are some others .......

1. It makes a barrel more rigid. The flutes make it harder for the barrel to flex. (I'm sure someone won't agree)
2. The flutes create more surface area on the barrel. More surface area allows for more heat exchange with the air, which allows the barrel to cool faster.

[StoneTower]

I will agree with #2, but #1 is not quite correct as I understand it. Fluting make a barrel stiffer than a barrel that is unfluted but only compared to a smaller diameter barrel that is the diameter of the bottom of the flutes. It might reduce the "sag" of the barrel because it removes some of the weight when looking at a fluted and an unfluted equal diameter barrel, but it might not as a fluted barrel is less stiff than a barrel of equal diameter to the outside of the flutes.

What can be said is that there is more surface area for cooling and that it is a great way to have a larger diameter barrel with less weight.

Fluting has very little if any effect on accuracy. There are several reasons (benefits) for fluting. The most comon and well known aspect is saving weight .... which you already know. Here are some others .......

1. It makes a barrel more rigid. The flutes make it harder for the barrel to flex. (I'm sure someone won't agree)
2. The flutes create more surface area on the barrel. More surface area allows for more heat exchange with the air, which allows the barrel to cool faster.

[Howitzer]

I personally have no idea but stole this from the Shilen website FAQ section.

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.

http://www.shilen.com/faq.html#question8

[ricsmall]

Howitzer,thats an interesting note, thanks.

[mtn_shooter]

edit: didn't see there was a page 2. I agree with what Howitzer said.

[stokesrj]

I think what Shilen said about fluting is marketing babble. It certainly doesn't hold up to real life experience. So, it seems to me they want you to think that if another barrel manufacturer flutes barrels it is inferior to their barrel. That simply isn't true. Shilen makes good barrels some are hummers some aren't, there are better barrels, and there are better that are fluted. It's simply a weight saving technique that produces a more rigid barrel than a round barrel of the same length and same weight. If done correctly, and many can do it correctly, it is not a detriment to accuracy. However if you don't need to save the weight why spend the extra to remove material, it's a lot less expensive to profile a round barrel and leave it at that. All of my hunting rifles, well nearly all, are fluted, some of them out shoot Shilen unfluted barrels. For instance my PacNor 6.5 STW has routinely produced .25 MOA groups and it is fluted.
Bob

[Smokepole50]

When I spoke with Krieger about fluting a barrel they said if THEY did it then it would be warrantied but if someone else did it then the warranty would be void. I think it has to do with stress induced into the barrel during the fluting process. I believe the fluting needs to be done prior to the final annealing and the final polishing of the bore, during the contouring phase to insure consistant bore size from end to end.

[fanofflyn]

I agree with Smokepole. But you can also take out the fluting stresses by cryo treatment of the barrel. I've not found that necessary for the accuracy that I can shoot. The main reason I have fluted barrels is because they look cool.

[Von Gruff]

From talking to my GS I understood that it is the depth of the individual passes that can have a detremental effect on the barrel stresses. If there is one shallow pass on the first flute then the barrel is indexed for the oposite flute with a coresponding shallow flute started re-indexed again like doing up the lugnuts on a wheel with shallow cuts being done each time then the stresses are not induced into the barrel and the nor is the bore effected in a negative way. it is when the flutes are cut to final depth in one position then starting on the next one that the stresses can be imparted to the barrel and accuracy is likely to go to pot.

[ericv]

I have no idea how fluting affects the barrel but I just ordered this one for my new .223 build, hopefully for a prairie rat hunt. It sure does look cool.

https://picasaweb.google.com/gevannos/Dr...8464794466

[Opus Dei]

When I spoke with Krieger about fluting a barrel they said if THEY did it then it would be warrantied but if someone else did it then the warranty would be void. I think it has to do with stress induced into the barrel during the fluting process. I believe the fluting needs to be done prior to the final annealing and the final polishing of the bore, during the contouring phase to insure consistant bore size from end to end.

More a result of how the barrel is rifled. I'm guessing Shilen doesn't recommend fluting since their barrels are button-rifled. It certainly can be done, if you relieve the incidental stress, first.

Kriegers are cut-rifled, and ought to take fluting without any special considerations. My thought is that they want the entire barrel production under in-house QC, rather than some Bubba f'n a blank up and trashing their name.