Ok I understand the inherent stiffness of the triangle. I understand the increase in surface area of a triangle. I under stand how this would be beneficial to gun barrels.
What I don't understand is:
Does it work?
Why the fuck has no one tried this sooner?
Would it be worth the shits and grins to do it to a 10/22 bull barrel this week ? :laughing:

i wouldn't do it to a barrel i cared about.

then again, i think the vtr barrels are ugly so i wouldn't even try it to a barrel i didn't care about.

Why the fuck has no one tried this sooner?

Because it would be uglier than a man's ass.

Would it be worth the shits and grins to do it to a 10/22 bull barrel this week ? :laughing:


By all means.

i wouldn't do it to a barrel i cared about.

then again, i think the vtr barrels are ugly so i wouldn't even try it to a barrel i didn't care about.

I am just shaving fatassedness off this 10/22 without loosing accuracy. Well that and its easier than fluting :laughing: I don't have CNC or skill like "some" people :flipoff2:

But the idea of a triangular barrel just intrigued me. Mainly due to the points I listed.

Screw a triangle. Go full hexagon or octagon. :flipoff2:

...
Why the fuck has no one tried this sooner?
Would it be worth the shits and grins to do it to a 10/22 bull barrel this week ? :laughing:

The Desert Eagle (http://www.magnumresearch.com/Desert_Eagle.asp) has a triangular shape. It's not a long gun but I think it looks triangular to me. :homer:

And yes it's worth the shits and grins to do it. :grinpimp:

Ok I understand the inherent stiffness of the triangle. I understand the increase in surface area of a triangle. I under stand how this would be beneficial to gun barrels.
What I don't understand is:
Does it work?
Why the fuck has no one tried this sooner?
Would it be worth the shits and grins to do it to a 10/22 bull barrel this week ? :laughing:

triangle barrel = the suck, A curricular barrel has infinity sides.

I wonder about harmonics... A round barrel would 'vibrate' in a more uniform manner. I wonder if a triangle barrel would do the same.

I don't think it would matter much with a .22 though...

Would make for a unique build...

All I know is that all the cheap, black 700 BDL's at the local gun shops have been replaced by the godaweful expensive VTR, and I resent triangular barrels based on that fact alone.

From the Remington VTR:

http://www.remington.com/images/products/firearms/centerfire/700_vtr_muzzlebreak.jpg

From the Remington VTR:

http://www.remington.com/images/products/firearms/centerfire/700_vtr_muzzlebreak.jpg

a perfect example of the precision and quality machine work at remington!



:barf::barf:

From the Remington VTR:

http://www.remington.com/images/products/firearms/centerfire/700_vtr_muzzlebreak.jpg

Needs less triangulation:laughing::flipoff2::laughing:

Because the circle is the most efficient use of materials.

Screw the nay-sayers. Triangle it and duracoat some hello kitties on it

Doc Are you going to mill the barrel while its still attached to the action? or are you going to indicate points on it before you take it off to mill

Screw the nay-sayers. Triangle it and duracoat some hello kitties on it

Doc Are you going to mill the barrel while its still attached to the action? or are you going to indicate points on it before you take it off to mill

IIRC 10-22's have a large groove in the bottom of them that's used for retention.

Because the circle is the most efficient use of materials.

In what way?

You still have symmetries. The barrel is more or less a cantilevered beam. In theory you still have rigidity in the vertical plane with the triangle. But lose stiffness left to right

If everything is perfect, in theory you'd only have oscillations in the vertical plane, as everything from left to right is counter balanced by a symmetric element.

I really have no clue if it would help or not. I'd like to think that Remington put some research into it and actually made a few and shot them first...but they way things are done now a days.

You pretty much have to rebarrel a Remington from the factory anyways, so who cares what shape the barrel is?

Because the circle is the most efficient use of materials.
For torsional stuff that's true. Cantilevered beam is more indicative of what a barrel is.
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Some interesting stuff about barrel harmonics.

http://www.varmintal.com/aflut.htm

http://www.varmintal.com/aeste.htm

http://www.varmintal.com/atune.htm
________
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a perfect example of the precision and quality machine work at remington!



:barf::barf:

Makes me feel better about the parts I mangle on my lathe! :laughing:

Thank you Remington, you're the best!

I'd like to think that Remington put some research into it and showed a few rich guys pictures of the newest baddassest tacticoolest bolt rifle and they responded with "oooh, ahhh, that's my favorite".

Fixed.

I was thinking more like mall ninja tactikool, white males, 20's-30's age, not particularly wealthy.

Rich guys would go straight for the AI.
________
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When we were at the range shooting for the "paper plate" thread, I asked the gun behind the counter about one that they had for sale. His response was "I don't really know what the purpose is, and I think it's ugly as hell, but a lot of people think they're cool and spend good money on them."

He was smiling the whole time! :laughing:

In what way?

The most area with the least amount of material.
Have you ever figured the most efficient use of 100' of fence?
You get more area enclosed with a circle.

Also read what atbliss posted about barrel harmonics. Have you ever seen a square/triangle tube on an organ, musical instrument, etc?

The only plus side is the ability to disapate heat. The more surface area, the more heat is lost. That is why many barrels are fluted. They keep the circular shape, with more surface area.

Think about the machine process of building a barrel. It is easier to keep it uniform using a circular shape. The barrel is chucked into a lathe for both the inside and outside. You have a uniform wall thickness, rigidity (modulus), etc. A circle is a much more forgiving shape mechanically and regarding physics.

Harmonics is how a barrel acts like an open ended pipe (essentially that is what it is). To tune the barrel, you change the length so the wave length is evenly divided into the length of the pipe. The BOSS system essentially allows you to tune the barrel by adjusting the effective length. It is a damper that changes the barrel harmonics. Prior to the BOSS system, you had to tune your loads to the barrel. This is done by adjusting the velocity of the projectile, and resultant wave, to the length of the barrel.
Once you find the load that hits the sweet spot, accuracy improves.
That is why hand loaders will load 5 with a certain charge, go up 1/2 a grain more of powder and load 5 more. Then you shoot 5 shot groups to determine which groups the best. Once you get two that are the most accurate, you make 0.1 grain adjustments to find the most accurate load.

When a rifle is fired, the barrel actually whips. If the wave length of this energy wave does not cancel itself out, it is out of tune. You get wave propogation that will whip the barrel unevenly. When you get the load that allows the returning wave to be the same frequency as the crests and trough cancel each other out.

That is a brief laymans description. I'll see if I can find a link that shows it graphically, because it is easier to understand that way.

http://www.shootingsoftware.com/barrel.htm

Same main page at atbliss, but shows a graphic that exagurates whip.

http://www.varmintal.com/amode.htm

http://www.rifle-accuracy.com/harmonics.htm

For torsional stuff that's true. Cantilevered beam is more indicative of what a barrel is.

the barrel undergoes torsional load when it's fired

The only plus side is the ability to disapate heat. The more surface area, the more heat is lost. That is why many barrels are fluted. They keep the circular shape, with more surface area.


problem with is that your surface area will go down if you mill an existing circular barrel to a triangle.

if you were starting with a new piece of metal, then you can make a triangle barrel that is big that once milled has more surface area than a circular one

Also read what atbliss posted about barrel harmonics. Have you ever seen a square/triangle tube on an organ, musical instrument, etc?

Someone is forgetting the musical triangle :flipoff2::flipoff2:
http://www.istockphoto.com/file_thumbview_approve/3149697/2/istockphoto_3149697_musical_triangle.jpg

fluted barrels may cooler faster than non fluted but they definatly heat up faster. weight savings and cdi factor is the real reason for fluted barrels.

now for the engineers out there, which barrel is going to be more rigid. they are all based on a .5" radius starting at the center of the bore. the triangle barrel would be 22.5% lighter than the round. the fluted barrel would be 17.5% lighter than the round. in reality, the percentage of weight loss would be much lower since the entire barrel is not fluted/triangulated.

now for the engineers out there, which barrel is going to be more rigid.
The one with the greatest cross section.
In this case, it would be the circular barrel.

The one with the greatest cross section.
In this case, it would be the circular barrel.


that is my thoughts exactly. i think order of most rigidity to the least would be the round, fluted and then the triangle.

From the Remington VTR:

http://www.remington.com/images/products/firearms/centerfire/700_vtr_muzzlebreak.jpg

Think it needs about 3 more flats to be aesthetic in my book... :D

D.

Someone is forgetting the musical triangle :flipoff2::flipoff2:
http://www.istockphoto.com/file_thumbview_approve/3149697/2/istockphoto_3149697_musical_triangle.jpg

That is a rod with a circular cross section bent into a triangle and tuned for the length of the sides.

the barrel undergoes torsional load when it's fired
how so?

how so?

I would guess its the resistance of the rifling. I could be way off.

how so?


something about forcing a bullet to spin over 200k rpm in a very short period of time would be my guess.

I would guess its the resistance of the rifling. I could be way off.

something about forcing a bullet to spin over 200k rpm in a very short period of time would be my guess.

yep, as I understand it, the barrel undergoes axial and torsional loading along and as the bullet travels up the barrel.

I think I remember seeing a slo mo of the effect on the barrel as it exhibited it's elasticity

Would a triangular barrel Harmonics be different than a round barrel aside from taking into account the rigidity of the barrel, in essence, make the harmonic mode shape (http://www.varmintal.com/amode.htm) more predictable?

I would guess its the resistance of the rifling. I could be way off.

something about forcing a bullet to spin over 200k rpm in a very short period of time would be my guess.

I'd buy that.

now for the engineers out there, which barrel is going to be more rigid.

In which direction though? Circle owns all in that comparison simply for having more material. However, if you're interested in rigidity in a...I guess you'd define it as a cut plane... then a circle doesn't win out as the most efficient use of materials.
________
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yep, as I understand it, the barrel undergoes axial and torsional loading along and as the bullet travels up the barrel.

I think I remember seeing a slo mo of the effect on the barrel as it exhibited it's elasticity

http://www.youtube.com/watch?v=s5pVya7eask

In which direction though? Circle owns all in that comparison simply for having more material. However, if you're interested in rigidity in a...I guess you'd define it as a cut plane... then a circle doesn't win out as the most efficient use of materials.

in every direction a barrel would be subject to. all of those shapes fit in the same radius from the bore centerline. the fluted barrel and triangle barrel have the same minimum thickness. i used 1" diameter in that drawing since i consider that to be the max dimension someone would consider for a barrel. i could have made the triangle like this and kept the same minimum wall thickness but then the weight is only 7.5% less than the round and the max dimension is 1.299" instead of 1" of a round.

so learn a n00b on that remington barrel, whats soo booger about it you lothing lathe operators? :confused: :D

so learn a n00b on that remington barrel, whats soo booger about it you lothing lathe operators? :confused: :D


the course and inconsistent tooling marks on the muzzle are bad cosmeticly. those same tooling marks in the crown are sure to cause accuracy problems.

oh so your talking about where they parted the barrel off at the end? they shoulda done a cleanup at the end after parting the barrell then.......

right?

the course and inconsistent tooling marks on the muzzle are bad cosmeticly. those same tooling marks in the crown are sure to cause accuracy problems.

That and I feel that cutting into a rifled barrel to port it rather than adding a brake is incredibly stupid. I also think that it's an overpriced marketing gimmick on the part of Remington.

700 SPS, .308: $620 MSRP
700 VTR, .308: $808 MSRP

$188 nets you a slightly different stock, an extra sling swivel, and a triangular barrel.

oh so your talking about where they parted the barrel off at the end? they shoulda done a cleanup at the end after parting the barrell then.......

right?

yes. instead of lopping off the end of the barrel in a harbor freight chop saw and cutting the crown with a dremel tool, it should have been been cleaned up on a lathe. most factory rifles will benefit from a precision cut crown but that one actually looks terrible to the naked eye.

You guys are forgetting one important thing- if you made the barrel really triangular (as in the picture above), you could sharpen the edges like a knife- ta da, built in bayonet!!

Or for the ultimate in badass, one edge with a knife blade, one with a saw blade and the last edge with a fish scaler.

Now put that in your BoB.

In which direction though? Circle owns all in that comparison simply for having more material. However, if you're interested in rigidity in a...I guess you'd define it as a cut plane... then a circle doesn't win out as the most efficient use of materials.

Considering the loads on a barrel are in the XYZ plane (torsional and bending), the circular is the most efficient use of materials.

In the manufacturing process, the circle is the most efficient.
Steel to manufacture barrels is produced as round stock.
Setting up the stock in a lathe, the manufacturer can cut the contour (taper from breech to muzzle), rifling, and thread the barrel all at the same station.

I am sure that all shapes and sizes of barrels has been tried.
The circle is what we are left with performance wise because of the XYZ loading, the cross section is consistent in all directions (opposed to an I-beam that is strong in only one direction).
Consistent performance dictates round barrels, secondary is cost.

Will a triangle barrel work?
On a 22, short barreled pistol it would probably be fine. The 22 doesn't have enough energy to effect the steel. The pistol barrel is short, tolerances are sloppy. They are generally inaccurate that you would probably not ever notice a loss in accuracy any way.

a precision cut crown

That is the most important part of a rifle barrel.
That is why you should clean a rifle from the breech, or with a rod guide.
Most people do more damage cleaning a gun, than they ever do from shooting. Most of that is due to crown damage.

That is the most important part of a rifle barrel.
That is why you should clean a rifle from the breech, or with a rod guide.
Most people do more damage cleaning a gun, than they ever do from shooting. Most of that is due to crown damage.

yup. I could make a question mark profile barrel with a clean crown and it would shoot a stupid amount better than a normal barrel with a shitty crown.

I have had rifles dropped off that "shoot like shit" and a 15min with a hand crown cutter and some oil and it it shooting like it should.

http://www.youtube.com/watch?v=s5pVya7eask

that's a good example but it seems like I saw a bull barrel from the muzzle end and you could see the rifling or either it was fluted. You could see the end of the barrel twist and flop like it was fluid

You guys are forgetting one important thing- if you made the barrel really triangular (as in the picture above), you could sharpen the edges like a knife- ta da, built in bayonet!!

Or for the ultimate in badass, one edge with a knife blade, one with a saw blade and the last edge with a fish scaler.

Now put that in your BoB.

and at the muzzle, you could recess the crown so that it has a proper one, but continue the ends of the angles of the triangle further so that they come to a point and be a super tactical CQB muzzle end

edited for content :)

I think NONEYA on pre-ban had a triangular barrel made for an AR. Saw a pic of it once and never heard anything else about it again.

Warning: This is what happens when a engineer mixes his hobbies late at night. :shaking: Jeeps, guns, sailing (you'll see), and engineering all in one thread!

The over simplified version of calculating stiffness is the height cubed times the width divided by the length squared. This gives you an idea of what helps and hurts the most. The weight is just the cross section area times the length. For example, adding X length adds X weight and cuts the stiffness by X squared. Adding X to the radius of a round barrel adds X cubed stiffness but only X squared weight, so a 1" round barrel is 49% stiffer than a 7/8" barrel but only weighs 30% more.

The trick with more complicated shapes such as a square or triangle is to break it into pieces. For a square barrel bending vertically, you have a radius equal to the height of the square from the center of the bore to the center of the face (not the point) and a width equal to the full width of the barrel face. In that case, it is clear that the material at the points is contributing very little stiffness relative to its weight since it is adding more to the width and less to the radius. On the other hand, if the force is from point to point, the radius is now measured to the points, and is much larger, which contributes greatly to its strength for the weight. The material at the other two points is contributing nearly nothing to strength though and doubling the weight. This makes sense since an I-beam has the material removed from the middle and added to the ends. It is very strong in the one direction and weaker across the beam. It is designed to take the load vertically, but not across it horizontally.

This means that anything other than a round barrel has axes that resist bending more and others that resist less. The square is weaker through the faces, and stronger through the points. Add more faces and the difference gets smaller and there are more of these axes.

The symmetrical shapes with an even number of features (points, faces, or flutes) have an even number of evenly spaced strong and weak axes. The square has 2 strong axes through the diagonals, and 2 weak axes through the faces. An octagon has 4 strong axes and 4 weak axes.

Shapes with an odd number of features such as a triangle have a strong and weak axis stacked since there is a point with a large radius and little width opposite the face with a smaller radius and larger width. These cancel in weird ways though since metal deforms differently in tension and compression. The barrel may whip up more than down for example. You really have to do an integral to figure out if the extra width at the face of the triangle makes up for its smaller radius, vs the point which has very little material but at a larger radius. When comparing for weight, the points win. Fluting or a spline shape gives you more points and less faces which really pushes the stiffness to weight up. Think of fluting more like adding ribs to stiffen a small barrel rather than removing metal to lighten a larger one, even though that is how one is actually made.

The ultimate shape in theory (though ridiculous in practice) is a thin walled barrel inside a larger thin walled pipe with ribbing along the length to couple the two against bending and around the circumference to couple them against torsion. As the ribs get smaller and closer together, you actually approximate the structure of foam which is incredibly stiff for its weight when made with low-stretch materials.

The closest real-world example of this is the diamond stays and spreaders used to stiffen sailboat masts or antennas. The wires replace the outer pipe since it is supporting a tension load.

A thin barrel with rods sticking out radially in the middle with wires attached at the breech and muzzle and going over the rods forming triangles creates a huge radius for tons of stiffness and adds almost no weight. Using the low stretch fibers like the Aramids or even the crystal polymers like PBO would give you even better stiffness than steel since they stretch less, just like the synthetic winch lines. PBO is cool stuff, but is $12 a foot and breaks down in indoor lighting within hours unless it is sleaved:eek:. Don't expect to see winch lines made from it any time soon.

http://www.mini12.ca/public_html/images/sail_rigging_pics/mast1.jpg

I'm off to grab some armored underpants to prepare for the nerd bashing that is headed my way...

Bryan.

Fluting or a spline shape gives you more points and less faces which really pushes the stiffness to weight up. Think of fluting more like adding ribs to stiffen a small barrel rather than removing metal to lighten a larger one, even though that is how one is actually made.

Bryan.


Splines eh?

Who wants to bore out an axleshaft.

That would be gunfuckery at it's finest.


Thanks for the good read Bryan.

rigid as in stiff? They all have the same stiffness if they are built from steel.. :flipoff2:

otherwise it was already mentioned, most cross section wins the strength, bending and torsional.

and while a triangluar barrel may have more surface area unless there is cooling by convection (wind) then it's going to cool slower then a circle. Conduction is based on the amount of material.

The ultimate shape in theory (though ridiculous in practice) is a thin walled barrel inside a larger thin walled pipe with ribbing along the length

Keep thinking onto the next step.
A thin walled barrel wrapped with strong fiber that doesn't conduct heat.
This was done in the 90's commercially. The tests were great, accurate, and light. Shoot all day and the barrel never heats up.

My problem with it is that the carbon fiber wrap doesn't have the elasticity that steel has. I suspect after years of use, fiber break down occurs and accuracy is lost.

I'll be checking to see if they are still manufacturing them and installing them on high powered rifles. I'd like to see a handful of 10 year reports from people that really shoot alot.

Edit: They are still in production
http://home.alltel.net/mdegerness/

Custom bolt gun with carbon barrel $3800.
http://bettincustomguns.com/Predator%20Composite/Predator%20Composite.htm
Used ones for $2500.

I remember Christensen Arms having them.
http://www.christensenarms.com/rifles.html
Just a measley $3900. :laughing:

BUT Wait you a laser engraved logo and
The rifle is customized with the Christensen Arms large diameter, high-strength, ultra-light, high modulus graphite -epoxy barrel casing applied over the factory-grade steel barrel.
:laughing:

Keep thinking onto the next step.
A thin walled barrel wrapped with strong fiber that doesn't conduct heat.
This was done in the 90's commercially. The tests were great, accurate, and light. Shoot all day and the barrel never heats up.

My problem with it is that the carbon fiber wrap doesn't have the elasticity that steel has. I suspect after years of use, fiber break down occurs and accuracy is lost.

I'll be checking to see if they are still manufacturing them and installing them on high powered rifles. I'd like to see a handful of 10 year reports from people that really shoot alot.

Edit: They are still in production
http://home.alltel.net/mdegerness/

I recall 10-22 barrels that were a rifled steel sleeve within a larger diameter carbon fiber tube. I am unclear if the dead space between was hollow or filled. Thinking more about that now, I wonder if the barrel sleeve was supported at any points along it's length to counteract sag?

Splines eh?

Who wants to bore out an axleshaft.

That would be gunfuckery at it's finest.

We (Pete and I) talked about splining a barrel on here a while ago... I'm pretty sure I can physically cut splines into one, but the ability to cut splines doesn't necessarily translate into having any clue of what I'm doing. :laughing:

I recall 10-22 barrels that were a rifled steel sleeve within a larger diameter carbon fiber tube. I am unclear if the dead space between was hollow or filled. Thinking more about that now, I wonder if the barrel sleeve was supported at any points along it's length to counteract sag?

The barrels are very thin steel barrels wrapped with carbon fiber, there is no hollow space.

Rimfire barrels are pretty common. There is little energy and probably would last a long time.

Center fire rifle barrels are a different story because the force.
Many modern rifles have a short barrel life any way. IIRC the 7mm-STW is 1500 rounds. I don't know what standard they are appying, if is it MOA or throat erosion.

I just wonder what the life of a carbon barrel is in regards to number of shots and time.

Keep thinking onto the next step.
A thin walled barrel wrapped with strong fiber that doesn't conduct heat.
This was done in the 90's commercially. The tests were great, accurate, and light. Shoot all day and the barrel never heats up.

My problem with it is that the carbon fiber wrap doesn't have the elasticity that steel has. I suspect after years of use, fiber break down occurs and accuracy is lost.



Don't see why it would, carbon is pretty inert to much heat, the resin or epoxy used to bond the carbon maybe an issue.

Carbon has a very high E compared to steel, or it's stiff, the elastic region for carbon is very short though.

I wouldn't think you would want something that doesn't conduct heat very well on the outside.. ie - insulating it.

I seem to remember years ago, some centerfire barrel manufacturer(s) discussing "laminated" barrels. A tube inside a tube inside a tube inside a tube.

Basically a barrel that could have rifling re-inserted and remain nearly constant on it's harmonics and accuracy.

I would have to have read it in a mag or something because this would have been pre-internet

I would have to have read it in a mag or something because this would have been pre-internet

What do you mean?

What do you mean?

i think it means your retarded, and that it was before everything was put on the internet :flipoff2:

I'm sure it might suprise some here, but there was a time when no one had computers at home, much less have internet access.

We (Pete and I) talked about splining a barrel on here a while ago... I'm pretty sure I can physically cut splines into one, but the ability to cut splines doesn't necessarily translate into having any clue of what I'm doing. :laughing:

Supposedly, a sharp V-shape at the bottom of a flute (like a spline) causes odd barrel harmonics. That's why barrel flutes are all round bottomed.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=644544

Carbon has a very high E compared to steel, or it's stiff, the elastic region for carbon is very short though.

That is my thought process.
Carbon has low elasticity.
Steel is elastic to the yield point and very resistant to stress fractures.