Math, science, and barrel fluting

[epc308]

These forums are populated by some of the best shooters and reloaders in the U.S. and some from Europe. Most of the best manufacturers contribute extremely useful information. Repetitive, redundant information is not useful.

Obviously I hit one of your nerves. Sorry about that!

What I wrote has every bit of bearing on what your initial post is about. Exactly as a matter of fact. Bruised feelings over not receiving the jumping for joy reactions and the pats on the back for math prowess is your problem.

This subject, as I stated, has been covered more times than most of us need to read again. You telling me that my 'snarky' comments have no bearing is just plain silly. And no I don't have to scroll by, ignoring this fact. Pointing this out is a way of trying to curtailing the next regurgitation for a few weeks anyway.

Have a great day!

I'm relatively new here, February of this year, and certainly haven't read every post about every subject to glean all of the wealth of available information.

I'm glad you are so knowledgeable and shared with the rest of us, but I must have missed your post from 25 years ago regarding this subject.

I didn't post for accolades and praise. I merely attempted to share something I learned, with a degree of detail many seem to ask for.

If the subject has been previously covered with the same detail, can you provide the link(s) to that information?

Please and thank you.

My most sincere apologies for being redundant and wasting your time with a subject I've never seen addressed.

I hope you also have a great day, kind sir.

 

[dryhumor]

Technically, aren’t flutes called lands...

Asking for a friend.

 

[Daddymac]

Everyone needs to consider, that just because you have beaten the dead horse over and over doesn't mean everyone has gotten a lick in. Use of the search function would lower the redundant post, but it doesn't always produce what you are looking for, and some people are trolls or just bored on a rainy day.

It is starting to rain here, so I will throw in my two cents with the OP.

Flutes do not make any appreciable difference function wise, weight, rigidity, or cooling, and appreciable is the key word. One thing they will do, however, is up your cool factor, and by an appreciable amount, fluted barrels just look better to me and and worth the price of admission based solely on the way they look.

 

[chkunz]

You can have a barrel of larger diameter but the same weight as a smaller diameter barrel by using flutes. So with flutes you have a stiffer barrel for the same weight. This is a simple concept but hard to explain and my explanation may need some help with someone that is a better wordsmith.

Yes, this has been discussed many times in many places and is common knowledge among most accuracy minded shooters. But we have new folks getting interested every day and I do not mind the repetition and even enjoy sharing it for some that will hear it for the first time.

Rather than criticize the OP I would encourage him, his next post could be something that teaches some of us "Old Dogs" something that we have yet to learn.

 

[davidjoe]

“Stiffness” could mean two things in the context of barrels. Resistance to a pipe bender would be the obvious first meaning. The fluted barrel of two blanks is going to lose.

A rod’s tendency to vibrate, that is held only by its end, and/or dampen itself from vibrations is another fair meaning of “stiffness” in the context of barrels.

Raw weight may increase vibrations. A cantilevered diving board with weights at the end (similar to heavy barrels with an inch in the receiver) will continue to undulate longer when upset than a lighter one will, - enter the subject of “nodes” or “tuners” and whether free floating barrels is a good idea in the first place or merely easy.

Two generations ago the heavy barrels of 40-x’s and Winchester 52’s were not free floated. They had adjustable pressure screws in the forend. One generation ago benchresters meticulously barrel blocked heavy barrels into the stock. Before both of those all service barrels were banded so the stock and barrel reinforced each other. Now, we are certain that 1/4 inch of clearance is a great idea, yet, if so, ... tuners? Loading nodes? Guys like to squeeze the barrel and forend together to test rigidity. How about simply combining them if flexibility is bad.

 

[Richard Coody]

You can have a barrel of larger diameter but the same weight as a smaller diameter barrel by using flutes. So with flutes you have a stiffer barrel for the same weight. This is a simple concept but hard to explain and my explanation may need some help with someone that is a better wordsmith.

Yes, this has been discussed many times in many places and is common knowledge among most accuracy minded shooters. But we have new folks getting interested every day and I do not mind the repetition and even enjoy sharing it for some that will hear it for the first time.

Rather than criticize the OP I would encourage him, his next post could be something that teaches some of us "Old Dogs" something that we have yet to learn.

As the OP said you might reduce the weight by 4 oz. I have checked into this because an appreciable weight reduction might make it worthwhile but reality is it just doesn't happen.

 

[Richard Coody]

“Stiffness” could mean two things in the context of barrels. Resistance to a pipe bender would be the obvious first meaning. The fluted barrel of two blanks is going to lose.

A rod’s tendency to vibrate, that is held only by its end, and/or dampen itself from vibrations is another fair meaning of “stiffness” in the context of barrels.

Raw weight may increase vibrations. A cantilevered diving board with weights at the end (similar to heavy barrels with an inch in the receiver) will continue to undulate longer when upset than a lighter one will, - enter the subject of “nodes” or “tuners” and whether free floating barrels is a good idea in the first place or merely easy.

Yep in will probably change barrel harmonics. But better or worse is not predictable.

 

[Dusty Stevens]

Lilja had a fluting weight calculator on their site. You can take off some serious weight with the right cutters. If it goes bad it goes from a 1/4” gun to a 1/2 at worst. Most times it makes no difference to the end user

 

[jelenko]

Old news and no reason to revisit the same flogged horse again.

We proofed these concepts 25 years ago with the same math and lab testing. We arrive at the same conclusions even way back then. You aren't adding anything new or startling, just more regurgitation.

Right. But others have brought up the question in some other threads.
If people could only ask questions about something that has been already proven somewhere by someone, there would be very few threads on this forum.

 

[INTJ]

Anyone winning long range benchrest with a fluted barrel?

Well I won several local matches in LR BR 14 years ago with a fluted barrel, but I don't run fluted barrels now

 

[INTJ]

Fluting makes the barrel droop less, though it would be easier to bend.

I recently weighed a fluted and non fluted #4. Both barrels Benchmark 26". The fluted one had a 3/4" shorter shank and was chambered in 340, the non fluted was chambered in 33-28 Nosler. The two cases are about 2 grains of water apart in volume. The fluted barrel was 2 oz lighter.

 

[epc308]

Lilja had a fluting weight calculator on their site. You can take off some serious weight with the right cutters. If it goes bad it goes from a 1/4” gun to a 1/2 at worst. Most times it makes no difference to the end user

Would an octagonal profile be the ultimate in fluting since you remove 8 slabs of metal down to the original OD, leaving only the corners?

 

[chkunz]

Fluting makes the barrel droop less, though it would be easier to bend.

This sounds contradictory, can you expand some on your meaning?

 

[hoz53]

Too much time on a rainy day-
Over the years, there have been many claims regarding barrel flutes. Gun writers in the glossy magazines have regurgitated the same "facts" over and over, making claims of increased stiffness, weight reduction, and increased surface area to improve the cooling.
A recent thread in the Varminter and Hunting section of the forum about contour swerved to the subject of fluting. That made me sit down to pencil whip the whole thing.
I used a typical barrel contour for calculations. 1.200" D x 3" L cylindrical section at the breech, 23" straight taper to an .800" D muzzle, for an overall length of 26". The total surface area is 85.2 square inches.
Typically, flutes do not extend to either breech or muzzle, so I used 6 flutes, 20" long for calculations.
For ease of calculations, imagine the flutes are square on the end, rather than radiused.
I determined cross section of the flutes by using a square inscribed in a 5/16 round, which resulted in a flute width of .220, .045 deep.
To cut a flute, you remove existing surface area. That results in 4.4 sq"x 6 flutes=26.4 sq".
85.2-26.4=58.8
The area of each flute is 4.9, for a total of 29.4 sq"
58.8+29.4=88.2 sq", for an increase of 3 sq" of surface area.
Not exactly cooling fins.
Weight reduction? Using the same parameters as above, each flute reduces the weight by .04lb, for a total 6 flute reduction of .24lb.
Increased stiffness? You need a machine to do yield strength comparisons. For best results you need dimensionally identical barrels cut from the same stick of raw material to assure the same metallurgical makeup. Machine one with flutes, another without.
Push or pull to failure, calculate the results.
If anyone has empirical data for that, please share.
Any and all comments are welcome, but no fires, please and thank you.

there has been some work done that showed the diameter of the bore changes when the barrel gets fluted or the diameter under the flutes is different from the rest of the bore. dont know if this is true or not but its enough reason for me to never want a fluted barrel. i dont care what it looks like, i just care about the performance . If im shooting fast enough for a barrel to overheat im not to concerned with the ultimate accuracy life of that barrel and 5 moa is probably good enough.

 

[hpshooter]

"These forums are populated by some of the best shooters and reloaders in the U.S. and some from Europe. Most of the best manufacturers contribute extremely useful information. Repetitive, redundant information is not useful.

I totally agree with all but the last sentence. Let me explain why, a function of this forum is to educate and cultivate new generations of precision shooters. While many of us were around this game for many years and have seen the same discoveries re-discovered many times a good percentage of the members have not seen this information before and benefit from it. Not trying to be an a--hat but I often skip through most of the rediscovery threads realizing they may be beneficial to someone with less time in the game.

 

[hogpatrol]

A little late to the party.

 

[Richard Coody]

"These forums are populated by some of the best shooters and reloaders in the U.S. and some from Europe. Most of the best manufacturers contribute extremely useful information. Repetitive, redundant information is not useful.

I totally agree with all but the last sentence. Let me explain why, a function of this forum is to educate and cultivate new generations of precision shooters. While many of us were around this game for many years and have seen the same discoveries re-discovered many times a good percentage of the members have not seen this information before and benefit from it. Not trying to be an a--hat but I often skip through most of the rediscovery threads realizing they may be beneficial to someone with less time in the game.

5 or 10 years ago this forum was the precision shooting forum. The authority on precision shooting. All threads were full of serious knowledge. I learned a lot and mostly kept my mouth shut.

Now this forum is overrun with shooters of all kinds who think they know what they are doing. Different disciplines do not have the same accuracy expectations, reloading techniques, gun handling tecniques, cleaning methods in fact very little in common. Three people on a thread with completely different shooting styles what do you expect. I have thought about just signing off but i see so much bad information being offered to new shooters I stick around. Sometimes I get disgusted and don't come back for a few weeks but it seems I always come back.

 

[C.E.Smith043]

The "increased stiffness" is compared to an unfluted round barrel of the same WEIGHT and length.

If you flute a barrel, it has less material, so it is less stiff than it was before fluting.

Spot on

 

[K22]

Not sure if fluting creates a stiffer barrel - my main interest was to reduce the weight on a 26" No. 5 contour (heavy varmint) barrel since I'm a varmint hunter first and foremost.

But to accomplish any significant weight reduction the smith had to mill in deep flutes so I'm not sure if I loss some "stiffness" but hell, the gun shoots lights out - 1/4 moa with tailored reloads - Douglas Match barrel in 223 Rem, 12" twist.

 

[K22]

5 or 10 years ago this forum was the precision shooting forum. The authority on precision shooting. All threads were full of serious knowledge. I learned a lot and mostly kept my mouth shut.

Now this forum is overrun with shooters of all kinds who think they know what they are doing. Different disciplines do not have the same accuracy expectations, reloading techniques, gun handling tecniques, cleaning methods in fact very little in common. Three people on a thread with completely different shooting styles what do you expect. I have thought about just signing off but i see so much bad information being offered to new shooters I stick around. Sometimes I get disgusted and don't come back for a few weeks but it seems I always come back.

Maybe creating a respectful dialogue might be helpful based on data and facts. I'll be the first to admit that I'm no where as knowledgeable as a lot of guys on this forum even after 50 years of shooting and reloading. I'm always willing to learn new methods to improve my shooting / reloading and I've learned quite a lot on this forum.

Sometimes I offer advice to new shooters in a effort to help them mostly based on my experience of shooting / reloading a lot for a long time but that doesn't mean I'm an expert. If the advice I offer is wrong I would welcome someone correcting it - I don't want to sent a new shooter down the wrong path. I also try to help an lot of young shooters at the range if they ask for help. I see a lot of bad shooting techniques at the range - e.g. resting the barrel directly on the front rest, etc.

Don't give up - offer your opinions and advice - we need it.