Questions on Fluting

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[ARCHIVED THREAD] - Questions on Fluting

Posted: 4/29/2004 4:41:48 PM EDT

Ok could multiple people and hopefully someone in the industry give me the real story plus their opinion on fluting barrels? I would like to know the advantages and disadvantages to doing it. I am planning on buying/building a new bolt rifle and planning on getting a heavy barrel. So guys fire away.

Posted: 4/29/2004 6:53:55 PM EDT

[#1]

Cools better

Lighter.

Bad Points - Cost

Posted: 4/29/2004 6:56:17 PM EDT

[#2]

Fluting does 2 things to a barrel. First, it increases the overall surface area therefore the barrel will cool faster than without fluting. Secondly, the nature of the fluting pattern also increases the rigidity of the barrel and helps reduce the "whiping" action as a round is fired through the bore.

My *opinion* on fluting is that it won't make that much difference on an AR type rifle but it will on a more precise bolt gun.

If you have the bucks and want to do everything possible to make this bolt gun as accurate as possible - do it.

CMOS

Posted: 4/29/2004 7:05:51 PM EDT

[#3]

CMOS, your second part is actually incorrect.

A barrel with less material will be less stiff, you cannot remove material and gain strength- however a fluted bbl weighing X will be more rigid than a non fluted bbl of the same weight.

Posted: 4/30/2004 7:52:09 AM EDT

[#4]

...a fluted bbl weighing X will be more rigid than a non fluted bbl of the same weight.

Yup...

I've owned a couple of AR's with fluted barrels, and from my experience:

They do NOT cool (noticeably) faster than an HBAR. Still too hot to touch, and stays that way for several minutes. I guess, on a bolt gun, it might make a 10 minute cooldown into an 8 minute cooldown.

Accuracy is not affected either positively or negavitely. People will tell you both. Of course I never fired an individual barrel for accuracy then had it fluted and fired again... BUT 2 barrels of same make and originally the same configuration didn't perform any better whether fluted or not.

BY FAR the biggest noticeable advantage to the fluting was the weight. My 14.5" fluted Bushmaster barrel was barely a couple ounces (undetectable) heavier than an M4 barrel, with a better balance (to me).

If I still had a big fat honkin HBAR bolt gun, I'd get the barrel fluted just for the weight savings.

Posted: 5/3/2004 8:41:08 AM EDT

[#5]

So Kevin you are saying a barrel will be less accurate after I flute it, because of the loss of material?

Posted: 5/3/2004 8:43:50 AM EDT

[#6]

Right now I am kind of leaning towards one of the Saveage 10fp tacticals .308 models. From some guys reports some of these with ssmall trigger modifications are shooting less than half an MOA. Would fluting the barrel on one of these reduce that accuracy?

Posted: 5/3/2004 9:15:28 AM EDT

[#7]

I spoke with Kurt at Kurt's Kustom Firearms about fluting a Savage 10FLP in .308. He said that this would certainly not be the first one he's fluted. In his experience, it WOULD reduce weight, and it WOULD NOT affect accuracy.

Posted: 5/3/2004 9:20:35 AM EDT

[#8]

Thanks I may do this especially for the weight savings since I would be carrying this for a deer rifle too.

Posted: 5/3/2004 2:47:00 PM EDT

[#9]

There is so much mis-information and dis-information out there on subject of fluting - ARGH!

Fluting increases the surface area of a barrel but DOES NOT SIGNIFICANTLY INCREASE COOLING RATE for barrel.

Fluted barrels GET HOTTER for the same number of rounds fired than unfluted barrels (higher peak temp due to lighter weight).

Fluting MAKES BARREL LESS STIFF AND LESS STRONG than the same barrel left unfluted.

Fluting looks COOL (if you like that kind of thing).

Fluting DOES reduce the weight of the barrel which causes the balance point of the rifle to move rearward.

The ability to shift the balance point, in my opinion, is the only valid justification for fluting.

Posted: 5/3/2004 3:41:51 PM EDT

[#10]

looks like I picked a controversial subject. Anyone from the industry want to chime in?

Posted: 5/3/2004 3:55:34 PM EDT

[#11]

LAV 25 bbls are fluted.
The LAV is a submoa platform with warshot ammo.

LAV bbls are fluted for several reasons.
Weight
Cooling

Weight - the weight to ridigity ratio is greater for a fluted bbl when both weight the same.

Cooling - due to the greater surface area the spines allow for greater cooling potential. The key to bbl heat issues is to remember the energy created from a round fired is a constant. x # of joules will go into certain materials and elevate the temp Y amount - While the exterior of a heavy bbl may remain cooler longer the chmaber and rifling have still been exposed to same energy it just will take longer to heat up the greater mass - the same goes for heat loss - the large mass has more energu trapped and thus takes longer to cool.

The same principle can be applied to small arms, and are.

Posted: 5/3/2004 4:02:03 PM EDT

[#12]

Thanks Kevin. You actually scientifically know the right answer Could you inform me what is the LAV 25?

Posted: 5/3/2004 6:44:13 PM EDT

[#13]

I've heard don't flute for the above reasons. You never see a true precision bolt action rifle with a fluted barrel. You find me a pic of a military sniper rifle with a fluted barrel.

Posted: 5/3/2004 7:57:20 PM EDT

[#14]

You find me a pic of a military sniper rifle with a fluted barrel.

Okay:

Hope you don't mind JC_

Military barrels aren't fluted on a widespread basis because they're EXPENSIVE compared to an HBAR or profiled barrel.

There is so much mis-information and dis-information out there on subject of fluting - ARGH!

Funny, I thought we more or less covered most of those points already, without the "ARGH!"

I don't mean you Mike Mills (really, I don't), but some people get downright WORKED UP over the fluted barrel topic. There are some who've read a couple of opinions that fluting decreases the accuracy of the barrel, and give valid reasons why they believe that is... However, in real life, it does not translate to measurable FACT.

Simple fact is, if you want a lighter weight rifle, then fluting is one option, especially if you're trying to keep it "stiff". Because, as we've said before, just not so simply (ARGH!

) a 3 pound barrel that is fluted WILL BE MORE STIFF than a 3 pound barrel that is NOT fluted.

But to end the discussion once and for all, ditch all of us armchair know-it-alls and head over to Kurt's Kustom and ask HIM about fluting your Savage and the effects it may or may not have. He's the expert.

Posted: 5/3/2004 7:58:38 PM EDT

[#15]

LAV 25 is a 8x8 wheeled APC used by the USMC - I should have specified the M242 25mm Bushmaster Chain Gun.

M11293 - that is cost...
Our McMillan TAC50's have fluted barrel BTW...

Posted: 5/3/2004 10:43:42 PM EDT

[#16]

Quoted:
There is so much mis-information and dis-information out there on subject of fluting - ARGH!

Fluting increases the surface area of a barrel but DOES NOT SIGNIFICANTLY INCREASE COOLING RATE for barrel.

Fluted barrels GET HOTTER for the same number of rounds fired than unfluted barrels (higher peak temp due to lighter weight).

Fluting MAKES BARREL LESS STIFF AND LESS STRONG than the same barrel left unfluted.

Fluting looks COOL (if you like that kind of thing).

Fluting DOES reduce the weight of the barrel which causes the balance point of the rifle to move rearward.

The ability to shift the balance point, in my opinion, is the only valid justification for fluting.

Bingo! Give this man a cookie.

Posted: 5/4/2004 12:44:59 AM EDT

[#17]

Some poeple like them, and some poeple don't. Weight and cooling are the main benefits from what I've heard, but the only ones I've built have not been for me.

Posted: 5/4/2004 11:27:25 AM EDT

[#18]

"Fluting a barrel helps with the compromise though. A fluted barrel retains most of the stiffness gained by increasing diameter, yet reduces the weight gain. And as a side benefit, fluting also increases the cooling rate of a barrel by exposing more surface area to the air. "

by Daniel Lilja, Lilja Precision Rifle Barrels, Inc.

Quote taken out of an article by Daniel Lilja.

www.riflebarrels.com/articles/longrange_shooting/ideal_barrel_308_tactical_rifle.htm

I'd listen to him before any one of you guys. Nothing personal, strickly business.

Posted: 5/4/2004 11:50:36 AM EDT

[#19]

Ok, you asked for it, here's the "real story":

Bushmaster: $50
Oly: $84 or $136
DPMS: $65
Fulton Armory: $125
Adco: $73.33 or $113.33
Lilja: $85, $115, or $150
Kreiger: $95 or $105
Hart: $120, $160, or $185
Pac-nor: $100 or $125

Shilen, from their website:
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.

Gale McMillan at TheFiringLine:
In the 1970s a bunch of target shooters were in our barrel shop and the subject of fluted barrels came up and the point of the discussion was that they wouldn't shoot well enough for target guns. That was the reason you never saw one on the line. After the discussion broke up I was talking about it with my brother and we decided to make a couple of barrels and flute them at a point in the manufacture that we thought it should be done. We made two and one was given to Harold Broughton of Big Springs TX and I put the other on my brothers gun. To make a long story short Harold won the NBRSA Nationals and Pat won the IBS Nationals and set two worlds records. I will say that while these two barrels were outstanding barrels it was in spite of being fluted and not because of it. After that everyone was fluting barrels and at any point from after they were made to before they were drilled. For my own point of view you couldn't' run fast enough to give me one that some one else had fluted. I once asked an other barrel maker why he fluted barrels and he answered . $2.00 a minute! That was what he made in fluting them.

$$$$$$$$$$$

Posted: 5/4/2004 12:17:24 PM EDT

[#20]

No! I have the real story!!

Accuracy International builds their rifles with flutting. H-S Precision builds their Rifles with Flutting.

Bushmaster: $50
Oly: $84 or $136
DPMS: $65
Fulton Armory: $125
Adco: $73.33 or $113.33
Lilja: $85, $115, or $150
Kreiger: $95 or $105
Hart: $120, $160, or $185
Pac-nor: $100 or $125

I guess all the above companies are wrong and don't know what their doing?

Any gunsmith can flute a barrel but if he doesn't do a good job then you have problems. That's what I got out of Shilens comments, that he didn't want anyone flutting his barrels.

McMillian..........well they make some good stocks...............

Posted: 5/4/2004 1:46:43 PM EDT

[#21]

Kevin B hit it on the head. The largest contributing factor to the strength of a column-or barrel-with all other things being equal, such as material composition, etc.- is the circumference and surface area of the column.

As Kevin stated, fluting removes material from the column-or barrel-which reduces it's strength because the circumference and surface has decreased-the key is it's strength has not been reduced by much.

A fluted barrel is considered stiffer than a non-fluted barrel when the two barrels in question are identical in weight. Even with the fluting the larger barrel still has greater circumference and surface area and therefore greater strength. The fluting has decreased its' weight to that of the non-fluted barrel while allowing you to retain the advantages of it's greater circumference and surface area.

heekma45

Posted: 5/4/2004 3:01:01 PM EDT

[#22]

Its a weight / ballance thing. Nothing more to it, objectively speaking.

Posted: 5/4/2004 5:55:57 PM EDT

[#23]

Quoted:
No! I have the real story!!

Accuracy International builds their rifles with flutting. H-S Precision builds their Rifles with Flutting.

Bushmaster: $50
Oly: $84 or $136
DPMS: $65
Fulton Armory: $125
Adco: $73.33 or $113.33
Lilja: $85, $115, or $150
Kreiger: $95 or $105
Hart: $120, $160, or $185
Pac-nor: $100 or $125

I guess all the above companies are wrong and don't know what their doing?

Wrong? Of course not. I believe in capitalism and market value and all that. I believe people should have whatever they want "just because." I don't fault companies for selling car-wings or spinny wheel hub-caps; let people have what they want. But I'm not going to pretend they make the car go faster.

If you take a barrel and flute it, it will cost some money, make the barrel lighter and less rigid, may or may not reduce accuracy by relieving stress that may or may not be present, and most of all, look neat.

Posted: 5/4/2004 6:19:18 PM EDT

[#24]

Jetlag,

Like I said earlier, I'll listen to the experts before I'll listen to you. Your opinion is lame. You have no background that would impress me to take your self-proclaimed superior knowledge above the listed major firearms companies.

But I'm glad you think my fluted barrel is neat. I think it's damn cool! And it shoots great too!

Posted: 5/4/2004 6:23:13 PM EDT

[#25]

Judging from the replies this is a pretty controversial subject. When I do build or buy my new bolt gun i will probably get the barrel fluted.

Posted: 5/5/2004 12:05:56 PM EDT

[#26]

Fluting looks cool and does lighten the barrel a little. I really don't believe there are any other OBSERVABLE advantages. Here's one of mine fluted, bead blasted, and O.D. polished.

Posted: 5/6/2004 10:55:25 AM EDT

[#27]

oh and heekma you stated that a fluted barrel has les surface area? How do you figure that? Obviously at least to me the fluted has more surface are just by looking at it.

Posted: 5/6/2004 1:48:19 PM EDT

[#28]

True precision do not have fluted barrels, taking mass away from the barrel does not help the stability. Heavier rifle tend to be much more accurate and fluting makes them lighter.

I photos of rifles used at a match where I live. Not a single one was fluted, I dont know if that says something but that is interesting.

[ARCHIVED THREAD] - Questions on Fluting

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