fluted barrel

Reduced weight for a given degree of stiffness, and bling. Against those, fluting adds around £150 cost to that of a plain round blank normally.
 
You can lighten up the barrel without losing any stiffness, and increase surface area for cooling in a match rifle. It won't shave off much weight until you get into the thicker barrels, like the 26-inch stainless on a Remington 700 in 7mm STW; I had one, and it made a difference in weight and balance there. I also built a .308 Win with a 20-inch heavy barrel (no taper) fluted, on a M700 short action, just to experiment, and it was very accurate and handy.
 
Are there any benefits to a fluted barrel.

Obviously, weight reduction.

A fluted barrel has a greater surface area than a round barrel and will dissipate heat at a greater rate.

However, the round barrel, having a greater mass, will need more heat to raise its temperature than the fluted.
 
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You can lighten up the barrel without losing any stiffness, and increase surface area for cooling in a match rifle.

Another plausible argument that fails - remove material and it will be less 'stiff' compared to original unfluted barrel, this myth comes from the sheet metal world that uses folds to 'stiffen' sheet, absolutely not applicable to a barrel unless you are a salesman.

As to 'cooling' again a myth, the more steel around the bore the better the heat transfer.

Only of use if you like the look.
 
Also an old idea as Hammerelli offered many styles of barrel fluting on their Martini target rifles and these rifles were used in top flight competition. Such as the Plympic when real shooting was the first medal awarded. Of course that was about 100 years ago now. There is a nice article in one of the old Gun Digests on these rifles and the firm Hammerelli.
 
Weight reduction, increased surface area for cooling, looks great in marketing material and increased "cool"ing at the range when your mates see it ;)
 
As to 'cooling' again a myth, the more steel around the bore the better the heat transfer..

If that was true a radiator would just be a solid block of metal with a few small water pipes in it. The fluting increases the metal surface to air ratio which is how it cools, hence the fins in a radiator. The actual amount it increases cooling in a barrel is probably negliable.
 
Blaser / Mauser fluted barrels with iron sights look mighty fine to me which I'd pay the extra for :)

other than hang that I wouldn't bother
 
It may be sales pitch and cool factor for most fluted barrels on hunting rifles, but there are practical benefits on some firearms, like a machinegun. I doubt the fluting on a Vickers was for decoration.

Actually, a fluted barrel can be more like an I-beam than a piece of folded sheet metal, insofar as being more rigid than a round beam. It also can change the harmonics from a slower movement of greater amplitude to a faster (higher frequency) movement of lower amplitude, which will result in smaller groups. A good $3,000 CAD program can model this quickly to assist in optimizing designs.

As for cooling, the larger mass of steel around the bore is going to transfer heat from the bore more quickly as thermal conduction seeks an equilibrium distribution of temperatures.... up to a point, at which the warmer outer surface of the barrel will begin to radiate heat and transfer heat to the surrounding atmosphere by nature convection and forced convection due to wind. The more surface available, the higher the rate of heat transfer. The closer some of that steel is to the bore, the higher the temperature, and the faster the rate of heat transfer to the atmosphere.

Weight distribution is a valid reason, and not just in my two examples of rifles I owned. I also owned two High Standard Olympic Citation .22 LR target pistols, one with a straight fluted barrel with ports near the muzzle for rapid fire and Duel, and the other with a long tapered and fluted barrel with two weights which could be added and set anywhere along the bottom, to get the balance to suit the shooter, for a complete match of slow, timed and rapid fire.
 
If that was true a radiator would just be a solid block of metal with a few small water pipes in it. The fluting increases the metal surface to air ratio which is how it cools, hence the fins in a radiator. The actual amount it increases cooling in a barrel is probably negliable.

I think there is a little truth in both statements.

Fluting has potential to create hotspots (insignificant in practical terms I would bet) within the barrel under certain (admittedly very) limited circumstances. The transfer of heat away from the bore is much more efficient through the metal but the transfer from the barrel to the air is, relatively, inefficient. So, under some circumstances the thicker areas of the barrel will be more able to remove heat from the bore to the surface of the barrel whereas because there is less metal heat in the thinner fluted areas is going to hit the metal/air barrier sooner and so conduction away from the bore will slow ever so slightly. Of course the heat will flow "around" the fluting but I'd suspect that under certain very specific circumstances and timescales then a fluted barrel has potential to get hotter in certain areas than it would if it were un-fluted. Of course the fluted barrel has a higher surface area and this will aid cooling on other timescales which is why I'm keen to highlight that my claims of hotspots are, probably, of no practical concern as they will be short lived and are likely to vary only slightly from the temperature of other parts of the barrel. Unfortunately I don't have the maths, or anything close to it, to quantify such hotspots. However, if you look at the calcs (I've seen them somewhere, though no idea where) the actual increase in heat transfer from a fluted barrel is, as nun_hunter says, likely to also be of no practical concern.

In terms of stiffness then you are cutting lots of material away from a pipe. It can't possibly be stronger when it ends up being made of less material. If you put your mind to it you could probably come up with a few experiments to do at home to demonstrate this.

In my experience only the hi-fi industry talks more mumbo-jumbo than the shooting industry when it comes to selling people stuff they don't need.
 
Actually, a fluted barrel can be more like an I-beam than a piece of folded sheet metal, insofar as being more rigid than a round beam.

Keeping it simple, because the round bit confuses things a little, an I beam is effectively a rectangular bit of metal with two large "flutes" cut out of it. Do you think it would be possible to demonstrate that the I beam is stiffer than the solid steel beam of the same dimensions?

Say I took an I beam that was 6 inches by 4 inches and 4 feet long and a solid steel bar that was 6 inches by 4 inches and 4 feet long and set them both up as cantilevers with a perfect suspension system. When I started hanging weight on the end which would "droop" the most for a given weight and which would fail first?
 
Deffo sucked in by the marketing, Caorach identifies the situation correctly, I beam hahahahah.... plonker
 
caorach and Sauer90,

The actual comparison would not be a solid beam of steel 6x4 (in, ft, cm, whatever) and an I-beam 6x4. It would be the fact that you can engineer what is called a "prismatic beam" which is stronger in one or more axes than a much heavier solid beam, rectangular or round. The fact that buildings and bridges are built from I-beams and not solid timbers should be evidence enough of that to anyone. The Eiffel Tower and Brooklyn Bridge were built to demonstrate these then-new construction and engineering methods, and they are still standing.

Understanding the heat transfer is simple: the barrel absorbs heat from the powder combustion until the exterior surface exceeds the surrounding air temperature, at which point it also begins to radiate heat and to transfer it to air at the surface. The heating of this air causes it to rise away from the surface and be replaced by cooler and denser air, which transfers in more heat energy. The greater the temperature difference and the greater the surface area of the barrel, the higher the rate of heat transfer out of the barrel. Adding some wind for forced convection and the delta T and surface area contributions continue to contribute even more.

It is too complex to get into the discussion of hollow beam deflection and vibration here, but I can direct you to whatever level of explanation you desire. I cut my software development teeth writing finite element analysis programs for predicting beam deflection, structural deflection of buildings and airframes, and heat transfer for all sorts of mixed materials. These programs later became part of what is now a larger commercial product, "NASTRAN". I still continue to occasionally develop external programs for kinematics and other machine design tasks, which are then fed back into CAD programs like Solidworks, Alibre, etc, for products I am designing, which have included small arms and components for them.
 
Mine both have coz i like them and I can, i don't know if they do what the trade say they do i just like them , it can also go for fluted bolts are they better with less ? Prob not
I would expect some nice chap will read this and have a heat temp laser and do a test same cal same amount of rounds be a good exercise and put this to bed
 
I think there is a little truth in both statements.

Fluting has potential to create hotspots (insignificant in practical terms I would bet) within the barrel under certain (admittedly very) limited circumstances. The transfer of heat away from the bore is much more efficient through the metal but the transfer from the barrel to the air is, relatively, inefficient. So, under some circumstances the thicker areas of the barrel will be more able to remove heat from the bore to the surface of the barrel whereas because there is less metal heat in the thinner fluted areas is going to hit the metal/air barrier sooner and so conduction away from the bore will slow ever so slightly. Of course the heat will flow "around" the fluting but I'd suspect that under certain very specific circumstances and timescales then a fluted barrel has potential to get hotter in certain areas than it would if it were un-fluted. Of course the fluted barrel has a higher surface area and this will aid cooling on other timescales which is why I'm keen to highlight that my claims of hotspots are, probably, of no practical concern as they will be short lived and are likely to vary only slightly from the temperature of other parts of the barrel. Unfortunately I don't have the maths, or anything close to it, to quantify such hotspots. However, if you look at the calcs (I've seen them somewhere, though no idea where) the actual increase in heat transfer from a fluted barrel is, as nun_hunter says, likely to also be of no practical concern.

In terms of stiffness then you are cutting lots of material away from a pipe. It can't possibly be stronger when it ends up being made of less material. If you put your mind to it you could probably come up with a few experiments to do at home to demonstrate this.

In my experience only the hi-fi industry talks more mumbo-jumbo than the shooting industry when it comes to selling people stuff they don't need.

Absolutely right! Shakti stones anyone? Lets not get into any cable debates...:doh:

For my sins, I'm an engineer. Removing steel to flute a barrel does nothing to increase strength. It does the opposite. Cooling advantages are over-stated because not enough sufficient surface area is created with most fluted barrels to make that much of a difference. As already said in other posts, the transition from the conductive efficiency of steel to air is a high impedance transition so very inefficient. It's partly why to get more performance for example out of old air cooled engines for motorbikes, air cooling was replaced with water cooled engines which are way more efficient.

A thick barrel, such as so called "varmint" barrels or heavy target barrels are more effective at removing heat away from the bore than thinner barrels such as sporter profiles by distributing the heat within a much larger mass of highly conductive steel. People often confuse cooling with surface area when in fact the mechanics involved are more concerned with cooling the rifling and internal barrel surface where thermal erosion can be problematic. Thickening the barrel transfers and distributes more heat away from the internal barrel surfaces, thus reducing risks of thermal erosion. The barrel being thicker also means a larger circumference = more effective cooling than a slender barrel. The barrel remains stiffer than an equivalent fluted barrel of similar outside diameter. However a fluted barrel will be stiffer than a solid barrel of a an external radius equal to the smallest external radius of a fluted barrel (the I-Beam example).

The main purpose of fluting seems to be weight reduction whilst maintaining adequate stiffness for any given outside diameter, with some minor cooling advantages, but start stringing shots from a relatively slender fluted barrel and hot spots can develop which create thermal erosion of the inside of the barrel at those points. Personally, I prefer to use a heavy non fluted barrel for target use for example and a traditional sporter profile for hunting.
 
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