I shot my 6mmbr this past weekend with 3 -65g Vmax bullets going into 1 TINY hole, a first for me... I used 32.0 g Varget for the first time,previously 31.0) & noticed a perfect "sine wave" of carbon,?) on the fired case neck & think I read somewhere that this is a good thing. Anyone have any info /thoughts on that? Thank you.
powder sine wave?
- Thread starter CT10ring
- Start date
CatShooter
"A sine wave of carbon"???
WHAT?
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WHAT?
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Forum Boss
Administrator
He is refering to the pattern of carbon residue on the neck of the case, the "edge of the burn" as it were.
Some folks think that a uniform sine-wave-like carbon trail on the neck of a fired case indicates that the powder is operating at optimal pressure and that the load is in tune. That's one theory at least.
For what it's worth, Lapua 6BR factory ammo,105gr) produces a very uniform up/down sine wave-shaped flame residue. The wave edges are wider and the peaks are a little more eliptical in shape than the illustration below. On my fired, factory-ammo 6BR cases, there are two carbon wave pattern peaks on the neck, diametrically opposed.
Some folks think that a uniform sine-wave-like carbon trail on the neck of a fired case indicates that the powder is operating at optimal pressure and that the load is in tune. That's one theory at least.
For what it's worth, Lapua 6BR factory ammo,105gr) produces a very uniform up/down sine wave-shaped flame residue. The wave edges are wider and the peaks are a little more eliptical in shape than the illustration below. On my fired, factory-ammo 6BR cases, there are two carbon wave pattern peaks on the neck, diametrically opposed.
CatShooter
"The edge of the powder burn leaves carbon trail similar to a sine wave"???
At the expense of annoying everyone, this is pure BS.
[Moderator: Catshooter, read my post on page 2 of this thread. This IS an observable phenomenon, in terms of how the carbon trail appears on the neck with certain powders and loads. Nobody says that the pattern IS a sine wave, only that the "carbon trail" looks like the up/down continuous pattern we're familiar with as a sine wave.
It is quite possible you've never noticed this on a case neck. But I can assure you it does show up -- it's not a rare phenomenon.
As to the question -- does the presence of this pattern really indicate something good -- I don't think there's any proof one way or the other.]
Having once spent seven years as a gunsmith, and going back to college to become a research en-ga-neer, I will tell you this worse than a bad joke.
One of the current trends in shooting is to try to "scientificate" everything.
I mean, like, when you say "carbon sine wave" it sounds so... well, you know, like "scientific", Dude.
You see a spot on a case... "It is from the internal resonating of the powder grains in the flow of the internal shock wave caused by the vibration of the gases from the primer, because it is in tune with the moon."
As an "en-ga-neer", let me explainifiy SINE WAVE.
The sine wave is a graphical depiction of an X-Y scale of the changes of an "anything" that follows a specific mathematical pattern. It is NOT a real, physical "thing".
I'll say that again... The sine wave is NOT a real thing, it is a graphical depiction of mathematical formula - nothing more.
So you cannot get a "sine wave" of a powder burn. There is no such thing. There is nothing in burning powder that creates an energy distribution that even comes close to the math of a "sine wave".
Saying you see some sine wave on your case mouth and it means something magical...
... is the same as saying that you see the face of Jesus in your morning waffle, so you are going to be lucky and take the day off and buy lotto tickets.
Sine waves on case mouths is silly non-science, made up by people that want to sound scientific about a smudge.
[Catshooter -- Nobody is saying the carbon trail IS a sine wave. The point is simply that it looks like a sine wave, for want of a better graphical analogy. Call it "up and down teeth" if you will. But the presence of such a pattern does occur. WHY it does, I really don't know.]
The biggest problem with stuff like this is, that someone that knows nothing about science, makes this stuff up, and all the new guys read it, and it sounds Soooo scientific, that they repeat it, trying to sound scientific... and it gets passed around, until it gets a life of it's own.
Then people defend it to the point of embarrassment, because they have heard it and it "sound so good"... in spite of the fact that they have no idea what they are defending, or what they are talking about... and it keeps on going.
Mean while, the true edu-ju-ma-cated folks just sit back and laugh.
If someone wants to believe in carbon sine waves, that's fine, but I would not recommend passing it on to others that have a science background - they will laugh at you when you leave the room.
Now that I have pissed everyone off, I'll go back to bed and invent some new case flame pattern - maybe I'll see the image of Jesus on my next batch of primers. Then "HE" will guide my bullets.
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At the expense of annoying everyone, this is pure BS.
[Moderator: Catshooter, read my post on page 2 of this thread. This IS an observable phenomenon, in terms of how the carbon trail appears on the neck with certain powders and loads. Nobody says that the pattern IS a sine wave, only that the "carbon trail" looks like the up/down continuous pattern we're familiar with as a sine wave.
It is quite possible you've never noticed this on a case neck. But I can assure you it does show up -- it's not a rare phenomenon.
As to the question -- does the presence of this pattern really indicate something good -- I don't think there's any proof one way or the other.]
Having once spent seven years as a gunsmith, and going back to college to become a research en-ga-neer, I will tell you this worse than a bad joke.
One of the current trends in shooting is to try to "scientificate" everything.
I mean, like, when you say "carbon sine wave" it sounds so... well, you know, like "scientific", Dude.
You see a spot on a case... "It is from the internal resonating of the powder grains in the flow of the internal shock wave caused by the vibration of the gases from the primer, because it is in tune with the moon."
As an "en-ga-neer", let me explainifiy SINE WAVE.
The sine wave is a graphical depiction of an X-Y scale of the changes of an "anything" that follows a specific mathematical pattern. It is NOT a real, physical "thing".
I'll say that again... The sine wave is NOT a real thing, it is a graphical depiction of mathematical formula - nothing more.
So you cannot get a "sine wave" of a powder burn. There is no such thing. There is nothing in burning powder that creates an energy distribution that even comes close to the math of a "sine wave".
Saying you see some sine wave on your case mouth and it means something magical...
... is the same as saying that you see the face of Jesus in your morning waffle, so you are going to be lucky and take the day off and buy lotto tickets.
Sine waves on case mouths is silly non-science, made up by people that want to sound scientific about a smudge.
[Catshooter -- Nobody is saying the carbon trail IS a sine wave. The point is simply that it looks like a sine wave, for want of a better graphical analogy. Call it "up and down teeth" if you will. But the presence of such a pattern does occur. WHY it does, I really don't know.]
The biggest problem with stuff like this is, that someone that knows nothing about science, makes this stuff up, and all the new guys read it, and it sounds Soooo scientific, that they repeat it, trying to sound scientific... and it gets passed around, until it gets a life of it's own.
Then people defend it to the point of embarrassment, because they have heard it and it "sound so good"... in spite of the fact that they have no idea what they are defending, or what they are talking about... and it keeps on going.
Mean while, the true edu-ju-ma-cated folks just sit back and laugh.
If someone wants to believe in carbon sine waves, that's fine, but I would not recommend passing it on to others that have a science background - they will laugh at you when you leave the room.
Now that I have pissed everyone off, I'll go back to bed and invent some new case flame pattern - maybe I'll see the image of Jesus on my next batch of primers. Then "HE" will guide my bullets.
.
So I'll preface my post by saying I don't know enough about shooting to know if a sine wave profile on the case is a good thing or a bad thing.
But I am an en-ga-nerd, and thus have to discuss the metaphysics of a sine wave. So get your popcorn ready. TO is out of season, maybe he's even reading this...
So I think that a sine wave is a real physical thing. It shows up in geometry, which I believe is real and the fact that geometry has proofs is just convenient. So either you can define a sine wave from geometry, or if you don't believe geometry is real, how about vibrations? If you look at the motion of a mass vibrating on a spring, you will see that the motion of the mass is sinusoidal with respect to time. A pendulum is a fine example of this type of motion. caveat in both these cases: I'm assuming its a linear vibration problem,the pendulum is at small angles or the mass oscillating is much larger than the spring supporting it).
If you want a spatial example of a sine wave in nature, how about the mode shape of a vibrating string. A string has a number of orthogonal modes which, excluding bending stiffness,why you can't push on a string), are exactly sine waves. If you do forced oscillations, you can isolate a single one of these modes of the string. Again, so long as the vibration amplitudes remain small, its a linear problem which can be solved exactly.
I admit that I believe in math, but personally I just believe that math is a tool for solving useful problems. Perhaps catshooter would agree that a Fourier transform of the powder burn around the circumference of the case would be dominated by the second harmonic. It is unlikely that any of the harmonics would be zero; but the key point is that the overall effect appears to be sinusoidal.
I hope I didn't make anyone get a second bag of popcorn for my logic here. Most mathematical functions have some physical base, at least in my opinion. And I have no idea if its a good thing to have the burn look like that or a bad thing, I just felt like arguing the metaphysics of math for a bit.
But I am an en-ga-nerd, and thus have to discuss the metaphysics of a sine wave. So get your popcorn ready. TO is out of season, maybe he's even reading this...
So I think that a sine wave is a real physical thing. It shows up in geometry, which I believe is real and the fact that geometry has proofs is just convenient. So either you can define a sine wave from geometry, or if you don't believe geometry is real, how about vibrations? If you look at the motion of a mass vibrating on a spring, you will see that the motion of the mass is sinusoidal with respect to time. A pendulum is a fine example of this type of motion. caveat in both these cases: I'm assuming its a linear vibration problem,the pendulum is at small angles or the mass oscillating is much larger than the spring supporting it).
If you want a spatial example of a sine wave in nature, how about the mode shape of a vibrating string. A string has a number of orthogonal modes which, excluding bending stiffness,why you can't push on a string), are exactly sine waves. If you do forced oscillations, you can isolate a single one of these modes of the string. Again, so long as the vibration amplitudes remain small, its a linear problem which can be solved exactly.
I admit that I believe in math, but personally I just believe that math is a tool for solving useful problems. Perhaps catshooter would agree that a Fourier transform of the powder burn around the circumference of the case would be dominated by the second harmonic. It is unlikely that any of the harmonics would be zero; but the key point is that the overall effect appears to be sinusoidal.
I hope I didn't make anyone get a second bag of popcorn for my logic here. Most mathematical functions have some physical base, at least in my opinion. And I have no idea if its a good thing to have the burn look like that or a bad thing, I just felt like arguing the metaphysics of math for a bit.
CatShooter
willyCJ said:
I knew it...
I just knew it.
How did I know it?
A sine wave is not a physical think that you can pick up and put in a box - it does not come from burning powder.
When you can take the nodes of a guitar string and put them on a shelf, let me know.
I'd love to see it.
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A guitar string is actually a bad example. The wire used has a decent amount of bending stiffness. So I vote we don't use it.
Anyway, claiming you can't put a sine wave inside a box doesn't make much sense.
But back on the ranch, the powder burn profile looks more like a sine wave than a square wave, linear or quadratic profile. So can it be called "sine wave like" for lack of a better term?
Anyway, claiming you can't put a sine wave inside a box doesn't make much sense.
But back on the ranch, the powder burn profile looks more like a sine wave than a square wave, linear or quadratic profile. So can it be called "sine wave like" for lack of a better term?
CatShooter
billmo said:
It is pointless to call it "Sine wave like"... the patterns of smudge on the neck has nothing to with sine waves, or load accuracy or burning - it is just random.
[Moderator--your point that this is merely the artifact of the burn front is well-taken. But with some loads, and some powders, the pattern on the neck repeats. Therefore I don't think you can call it random. On my 6BR factory-loaded ammo, every fired case has a similar pattern, with two high points,and two low points) diametrically opposed.]
The are like images of a saint on a cheese sandwich, except you can't sell them on eBay for $22,000 :,
You might as well try to read the primer pocket residue to determine the loads. Maybe tea leaves?
[MODERATOR: That the pattern can appear, repeatedly, is a fact. Whether it is an indicator of something good, or something bad, or whether it is meaningless as an indicator of burn performance is open to question.]
Billmo... when you find all your old nodes, put them on eBay. They are worth a lot these days.
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Wow, passionate folks abound, but I'm not feeling the love! I was pleased with my tiny 6mmbr group, especially as I just began reloading last year. Maybe I should have said something to the effect of "is it a sign of correct amount of powder loaded when one sees this wavy, very symmetrical burned powder smudge on the neck of a fired case?" Mr Moderator has effectively repeated what I noticed. Guess I will answer my own question & say "possibly", as for the first time, I had shot a tiny group & for the first time, noticed this odd burn mark. Hey, I had never even seen a caliper until 8 months ago, and the learning curve is steepish.
HAPPY shooting, all. Gotta run, my grilled cheese is burning. Hey, what is THAT?
HAPPY shooting, all. Gotta run, my grilled cheese is burning. Hey, what is THAT?
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Forum Boss
Administrator
--Catshooter, nobody is suggesting that the pattern of the burn residue on the neck is actually a mathematical function.
We are merely using a known graphic shape to describe what can,and sometimes does) appear on a case neck. That's sort of like staring at a Volkswagon and saying "it looks like a turtle". No-one is claiming the VW IS a turtle.
Here no one is claiming the pattern of powder IS a sine wave, or the manifestation of a sine wave. As I noted, on my 6BR factory loaded ammo the "peaks" of the pattern are somewhat more eliptical than a classic sine wave pattern.
What IS interesting is that there are definitely two diametrically opposed high points, and two diametrically opposed low points, connected in a continuous curving line. That is, presumably, caused by a powder flash front that extends down the case neck like fingers.
This is not a "phantom" thing. It really happens. And it is NOT Random, as it appears on all the case necks of my fired, 6BR factory-loaded ammo.
Is it meaningful? That is to say, does the carbon-trail-in-a-wave-like-pattern really mean the powder is in an optimal pressure range,or sweet spot)?
Honestly I have no idea. Some folks think the wave-like pattern is an indicator of a "good" condition. Personally, I don't know if it's good, bad, or irrelevant.
If you think it's meaningless, that is fine. But the appearance of a sine-wave-like trail,or call it up and down teeth if you prefer), IS an observable,non-random) phenomenon.
CatShooter
I shoot a .262" 6mmBR and I have never seen anything like what you describe - nor have I ever seen it on any of the other rounds I load for... and I load and shoot a LOT.
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Dave223, Thanks for that. Whoever coined the phrase "ignorance is bliss" may have been onto something...! For what it is worth, I have really enjoyed gleaning information from this site, and truth be known, had a 6mmbr built for me, solely from reading about this caliber, having never seen any component. It just sounded like a better way to go than my Ruger #1 .243, which shoots quite well-for the 1st 4 rounds, anyway.
Then it turns in a single pellet shotgun. Not so with the 6br. Maybe I will market the Lapua sandwich. Moly sauce with that...?
Then it turns in a single pellet shotgun. Not so with the 6br. Maybe I will market the Lapua sandwich. Moly sauce with that...?
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