OCW Extended

23 February 2003, 14:52

Hot Core

quote:
Originally posted by denton:
1. If there were no barrel whip, bullets would pretty much leave the barrel in exactly the same direction.

2. OCW puts your bullet exit at one of the slower moving parts of the barrel whip arc.

3. Once you find that point for one load (say your 180 grain 30-06 bullet), other loads that give you the same POI should also be in the slow part of the arc.

Hey Denton,

1.Yes, but that is not reality.

2. HAHAHA Trick question. Actually, the best way to achieve this Goal is to use the never improved upon, non-Rookieized, original Creighton Audette Load Development Method.

3. Yes and No. The very best, most consistent, repeatable groups ALWAYS come from the "Apogee or Perigee" of the harmonic. Impacts made during the transition between the Apogee and Perigee will show up as some kind of an elongated pattern and can be in any direction.

Barrel harmonics are in a constant state of flux and vary from rifle-to-rifle, case-to-case, primer-to-primer, powder-to-powder, bullet brand-to-bullet brand, and of course shot-to-shot.

So, even though, "other loads that give you the same POI should also be in the slow part of the arc." may be on an Apogee or Perigee of a harmonic, the probability that it is a "duplicate harmonic" of the previous Load is pretty much impossible. Simple things such as the Variation in Bore Resistance between different bullets alters the burn rate slightly. And of course, that will change the "Barrel Time" for the bullet and it's Velocity.

But, you can still end up with the same Point of Impact even though the harmonic will be different. And if the second Load is consistently providing small, repeatable, well formed groups, then it has also found an Apogee or Perigee of that different harmonic.

23 February 2003, 15:07

<green 788>

Wow, Hotcore... It sounds like you've been doing your homework! [Smile]

ArkyPete, what you've mentioned is something I have considered, though in another way: I have wondered if one of the secrets to the uncanny accuracy of the Swedish Mauser rifles might be the front barrel band, which would have the effect of damping harmonics to some degree. So long as the damping action is consistent from shot to shot--and it usually is in these well bedded rifles--the barrel whip would be less likely to throw an off pressure shot wild.

That's just something to think about... In truth free floated barrels tend to be the most forgiving, but you can't argue with the success of the Swedes either...

Here is a link to my webpage where I explain some of the shortcomings of the Creighton Audette method (ladder test), for any interested...
http://home.earthlink.net/~dannewberry/_wsn/page4.html

The Audette method isn't an altogether bad way to develop a load, but I think the OCW method is much more likely to get you a good, resilient load. (And it seems that more and more well educated folks are agreeing with me...)

Dan

23 February 2003, 15:36

Gustavo

Hotcore, I agree to some degree... there is no way to test the validity of either method except by running hundreds of test, involving lots of combinations... possible ? yes feasible ? no

In other words, both methods show some merit regarding an ordered way to do things, BUT both lack any correlation to barrel whip, at least is mere speculation... nothing more than that.

There is zero evidence of such correlation.

I was thaught that in science, and ballistics is a science, one should PROVE and demonstrate! anything else... well, leave it alone.

Our sport is full of myths, we don't need another one!

BUT, I still think that both methods are meritorious in terms of the direction taken, but a resilient "load", a one where harmonics are somewhat "neutralized", is for sure beyond the scope of the test conducted by individuals!

You don't "demonstrate" Newtonï¿½s law by just leaving dropping free an apple!

23 February 2003, 15:47

<green 788>

Gus,

You might be interested in the shared experiences of the folks here: http://216.219.200.59/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic&f=1&t=001381

Note that only one of the respondents mention that the the OCW load of 45 grains of Varget with the 175 grain Sierra Matchking did not perform extremely well in their individual .308 rifles. (And note that a couple of the respondents mention trying the same OCW recipe in more than one rifle, again with incredible results).

The single respondent that was unable to use the OCW recipe was using a very short chambered custom .308 barrel and was therefore forced to seat the bullet too deep into the case. An understandable exception.

The rifles being shot by the respondents include Remingtons, Winchesters, Savages, custom Robars, and I believe a Ruger or two. All different rifles with different shooters--shooting one recipe into 1/2 MOA and better groups.

Now how could that be?

OCW loads work. The method works. Learn it, love it, live it! [Big Grin]

Dan

23 February 2003, 16:27

Gustavo

Dan,

Of course I agree that is sound theory relating one specific charge to produce a specific barrel vibration... but what I don' see is how such method is valuable in terms of the claims at hand.

For example, the way of selecting a powder, or a starting charges range... well there is nothing new there, my friend.

I'm absolutely not against trying new ideas, on the contrary!! but I want proof or evidence, where a sound math model is backed by field tests!

I'm sure that you are aware that harmonics is a field for itself and please, for the sake of us, fellow shooters, a graph showing a diagram of a "whip" is nothing more than nothing.

In other words, I'm not against "empirical thoughts and tests" but if we take that route, at least I'd like to see many recipes, for many powders and bullets, tested and tested by many shooters... then I'd say that there is enough evidence to prove that "empirical" method even without any stong theory behind it.

I really don't hate or love the OCW idea, but I disregard any "method" that have high claims, like this one, almost a NON PLUS ULTRA for us reloaders, without seeing theory and hard evidence.

For years I've been reading that penetration is a function of SD... well until I got tired of reading such POS... I wrote a letter to Rifle Shooter, critizing Craig Boddington statement on that matter... they printed my letter and zero response from Craig... In fact he never again mentioned that MYTH published HUNDREDS of times by many authors... or another Killing index developed by J.T Wootters... well that's another story.

And I'm seeing much of the same here...

I really appreciate the enthusiasm and the effort, but don't make such claims so lightly... just a well behaved opinion.

23 February 2003, 16:35

denton

'Scuse the rant, but misuse of the term "barrel harmonic" just grates on me. So everyone tune out for a minute while I rant.

When something vibrates, it is undergoing "harmonic motion", meaning motion that repeats itself. A "harmonic", on the other hand, is a multiple of the fundamental vibration frequency. So if your barrel is vibrating at 100 Hz, the second harmonic is 200 Hz and the third harmonic is 300 Hz. It is not correct to refer to the node of a harmonic, unless you are referring to motion that is taking place at one of the harmonics. "Node" and "pole" are good terms for this application for describing parts of the barrel whip arc.

Thank you all for bearing with me... I feel much better now.

From basic physics, the OCW method has to work. The genius of it is that you are replacing a test of spreads with a test of position, which requires many fewer shots for the same level of precision. The idea of doing it "round robin" is one way of "sorta randomizing", which, from statistics, is much more sound than not randomizing. It is refreshing to see someone actually employing sound procedure in their work!! There is soooo much of the other kind.

Dan, I've been turning this over in my mind, and there is one theoretical thing that I think I can contribute: With only a little work, I can tell you how many shots you have to fire per group, to distinguish a given amount of POI shift. Right now, I'm in an "Internet Cafe" in Bangkok, resting up for a big week ahead, leading a Six Sigma session. Maybe we can talk about this when I get back to the US, if you're interested.

My hypothesis is that once you establish an OCW for one load, any other load that gives you the same POI is very likely to be an OCW for that load, too. As I said, this is a statement or proposition to be tested.

23 February 2003, 17:21

<green 788>

Denton,

I'd be happy to discuss the idea. If you can come up with a statistical model that could be incorporated into the whole idea--that should be useful indeed.

Email me when you get to a point where we can talk.

I think that by simply testing some of the OCW load recipes I've identified, many folks might be convinced to give the method a closer look.

Thanks for your continued input,

Dan

23 February 2003, 17:23

Gustavo

"From basic physics, the OCW method has to work. The genius of it is that you are replacing a test of spreads with a test of position, which requires many fewer shots for the same level of precision. The idea of doing it "round robin" is one way of "sorta randomizing", which, from statistics, is much more sound than not randomizing. It is refreshing to see someone actually employing sound procedure in their work!! There is soooo much of the other kind"

Denton, from your foregoing rant, I had to conclude that you can correlate the OCW idea and derive a general theorem about this.

I'd love to see such explanation. Please, if you can extrapolate, to a general one I'd not mind to see real formulas.

Or, by the same token a sound explanation, citing physics principles, internal ballistics, and finally how all the pieces come together, including the notion that a "round robin" and a "position" shooting scheme could be applied to every rifle...

Keep posting, I'm interested !

24 February 2003, 00:44

denton

Gus...

Let me give your questions a try...

When you "drop the hammer", a shock wave starts down the barrel. Since it is propagating in steel, in it moving about 10X the speed of sound in air, and it arrives at the muzzle before the bullet does.

The effect of the shock wave on the muzzle is that it sets up a vibration at right angles to the barrel, so the barrel is vibrating up and down and sideways. Looking at the muzzle, the shape of the arc could be an ellipse, or a circle (in which case none of this will do you much good), or a straight line, or perhaps a figure 8. An ellipse is an educated guess at the most common shape. At any rate, it will serve as an example.

When the barrel is on the "side" of the ellipse, it is moving relatively fast. When it is near the "end", it is moving relatively slow.

Barrel whip is a well-known major component of rifle accuracy. Browning's BOSS system tunes the resonant frequency of the barrel to get the same result as OCW.

Every cartridge will have a slightly different transit time from "hammer drop" to muzzle exit. The resonant frequency of the barrel and the transit time determine where in the arc of barrel whip the bullet will exit.

Now think about two nearly identical cartridges, with slightly different transit times that have the bullet exit on the "side" of the ellipse. Their separation at the target will be relatively large, because the barrel covers more transverse distance when the bullets exit on the "side".

Next, think about the same nearly identical cartridges, but with the powder charge and bullet seating adjusted so the bullets exit on the "end" of the ellipse. Since the barrel is barely moving at this point, their separation at the target will be relatively small.

The basic physics of the situation says that minimum spread at the target coincides with having the bullets exit while the muzzle is in the slow moving part of its arc. Another interesting thing happens here, too. The load becomes "robust". By that, I mean that small changes in components make little change in the accuracy of the cartridge. That all has to happen because of the basic nature of harmonic motion.

That's the physics. Now for the statistics.

Guys routinely go down to the range and shoot a 5 shot group with Brand A, and get, say, a 1/2" group. Then they switch to Brand B, and get a 1 1/2" group. They then conclude that Brand A works great and that Brand B stinks. Unfortunately, the math does not support this conclusion.

Tests of variation are notoriously weak. A rifle with a true long term average 5-shot 1" group size will routinely produce groups from 1/2" to 1 1/2", with no change in the fundamental process. So the problem is that, because of the weakness involved in comparing spreads, judging a rifle's ability to group well requires a large number of shots. 5 is definitely not enough.

On the other hand, tests of means are much better. You get a much more precise answer with fewer shots.

So what OCW is take advantage of the well-established fact (look it up in Resnick and Halliday!) that minimum spread, minimum muzzle speed, and best robustness all happen at the same place in the muzzle arc. OCW watches for the region of minimum POI shift, which is relatively easy to "nail down".

The "round robin" method is "sort of randomizing". This is very sound procedure, since it chops up any lurking variables, and spreads them over the whole test. The lurking variable is still there, but it does not have near as much opportunity to trick you. This has been well-estabilshed test procedure for a lot longer than I've been around.

So that both the physics and the statistics.

24 February 2003, 03:18

Hot Core

quote:
Originally posted by Gustavo:
Hotcore, I agree to some degree... there is no way to test the validity of either method except by running hundreds of test, involving lots of combinations... possible ? yes feasible ? no

There is zero evidence of such correlation...

Hey Gus, I understand your skepticism of any “new to you” Load Development System. I also agree it “could take” many thousands of shots to prove how well one method works. The benefit you have in this situation is that the Audette Method has been in use by knowledgeable reloaders for many years who have used thousands of firearms with millions of shots sent down range. So, there is lots of “experienced” information available on how well it works.

Occasionally someone actually thinks they can improve on the original Audette Method, but I’ve yet to see anyone do it. For example, Denton mentioned the “Round Robin” portion of Rookiegreen’s MUC Load Method being a good thing. I disagree. If you were in a “Lab Environment” with controlled environmental conditions it would help “standardize” the data. However, these tests are not normally run by the average shooter in an underground tube with controlled environmental conditions. Due to that, the Round Robin will induce errors into the process, because the resultant time lag means the Range Conditions have changed.

Of course, the resulting Round Robin problems are much easier to see at the 300yd distance which Creighton Audette encouraged. Similar to variation being harder to detect with groups shot at 25yds rather than 100yds. But, if a person is using a firearm that is not capable of an “adequate performance level” beyond 200yds, then it does make sense to do the Load Development at some distance shorter than 300yds.

...

And Gus, here are Two Options that will let you to prove the validity of the never improved upon Audette Method to yourself. Option 1 provides a way for you to reach the correct answer for yourself, but is a bit time consuming and expensive. Option 2 takes much less time and also provides the correct answer. Here are the Options:

Option 1: Enroll in any school that offers advanced Math and Engineering courses. From taking these courses, you will easily understand in no uncertain terms why barrel harmonics vary. The only problem is if it has been awhile since your last formal Math or Engineering courses, then it may take a few fundamental classes to refresh your basic knowledge background prior to taking the advanced courses.

You will need (as a minimum) two advanced Math courses something similar to Foundations of Advanced Mathematics and Analytic Geometry and Calculus to establish a mathematical foundation to build the Engineering curriculum on. The first advanced Math course will deal with complex numbers, permutations and selections, probability, set theory and statistical inference, etc.

The second advanced Math course will deal with applications of derivatives, integration of basic forms, definite integrals, integration techniques, polar equations, parametric equations, empirical forms, moments (of area, of arm, of inertia), differential equations, simultaneous quadratic equations and toss in mind-stretching concepts such as the McClauren(SP?), Taylor and Fourier Series.

Not every concept in those two Math classes is needed for the Engineering course segments that eventually lead to clarity on firearm’s harmonics. But they provide a solid basis for you to be able to think your way through the logical process.

For Engineering courses, you need something similar to Mechanics of Materials and Engineering Mechanics to get into the heart of why harmonics are constantly changing variables when shooting. Here again, more advanced Engineering courses strengthen these basic concepts, but these are detailed enough to allow a person to realize how the Bullet Transition Physics really work.

Things you will learn in Materials courses include Stress/Strain, Material Properties, Strengths of Materials, Elasticity Fundamentals, Torsional Loading, Radial and Vector Analysis, Flexural Loading-Stresses, Flexural Loading-Deflections, Intermediate Beams (Integration, Area Loading, Superposition, Castigiano’s Theorem, Plastic Analysis), Combined Loading (Static and Dynamic), Column Loading, Repeated Loading, Connections (Stress, Loading, Ultimate Strength, etc.) and lots of stuff I’ve not thought of.

The Engineering Mechanics course will contain things such as Scalar and Vector Analysis, Moment of a Force, Composition and Resolution of Forces, Principal of Moments, Couples, Force and Mass, Resultants of Force Systems (concurrent / non-concurrent coplanar force systems), Centroids, Center of Pressure, Equilibrium (this is a very interesting one), Second Moments and Moments of Inertia, and good old Friction(Static and Dynamic) and more stuff I’m just not remembering.

Now that you have the knowledge to understand why the never improved upon Audette Method works, all you have to do is go shoot lots of firearms creating many groups to verify what you already know is true.

Knowledge plus Experience gets you to the correct answer.

Option 2: Find someone “you know” who has both a formal Engineering background with actual hands-on Design Evaluation Engineering experience and ask them.

If you structure the question so they are fully aware of what you are actually trying to understand, they will say, “barrel harmonics during the bullet transition are in a constant state of flux”. It is therefore imperative to be as consistent as possible, in each step of the reloading process, to reduce the variability as much as possible. It is also important to test the theory using a Method that allows you the best opportunity to detect variation in the data.

And as a bonus, that same Engineer can tell you that “the MUC Load concept is Full-of-Beans”. [Big Grin]

Seems to me I’ve heard that somewhere before!

24 February 2003, 04:38

<green 788>

A quotable quote come to mind:

If you can't blind them with brilliance, baffle them with bullshit!

(Hotcore, did you author that quote?) [Big Grin]

Dan

24 February 2003, 04:56

Gustavo

Dan, Hotcore :

This thread is getting fantastic!!

1) Hotcore displayed a great amount of humor!!
2) Dan, you are getting aggresive !!

It's a funny thing to see how some people "versed" in engineering could say a lot of nothing!!!!!

Let me say something about my own background.

I have a MS in Computer Science and Operations Research. In fact I developed a program called LoadBase 1.0 to share with my fellows, and of course, I had to develop my own math model to deal with external ballistics. Lots of guys here can give feedback on my work.

In other words, verifiable evidence... no craps of bla, bla, bla....

It is very common in science to encounter some guys that by adding and substracting many, many words "conclude" something that is ... irrelevant

Dan, HotCore, where did you learn your Engineering ??

I'm perplexed at the easy simplifactions made here!! Maybe NASA could be interested in hiring you !! and save millions for the taxpayers !!

Why is that these method got so little recognition ?

Hotcore, if you like, I can give you a lecture anytime on how science is developed... for example and for sure not citing a curricula... but showing hard evidence... humor is fine, science is another thing.

BTW, if you guys are happy with the OCW or Audette, ok be happy with them, because no one could get harmed!

But, please STOP claiming!!!!!!

Unless, of course, you can relate one thing to another... ok ??

Go back, burn more powder and came back with evidence, my fellow engineerssssssssss

24 February 2003, 09:45

<green 788>

Unfortunately, Gus, it appears that no amount of math, science, or anything else is going to convince you here. It appears that this has become some sort of a quest for you not to lose a debate...

Over the eons of human existence, there have been formulas and methods that were first noted to work, and only later scrutinized by science. Serendipity... And 99.997 percent of the time, you can bet that those who noted the usefulness of those formulas and methods were not the scientists themselves.

Did you know that for over 50 years some people have been putting a duct tape patch over their warts because someone, somewhere noted that the duct tape patch totally removed the wart faster and more efficiently than any medicines on the market? And just last month I heard of the scientific study on that matter, which did in fact conclude that the duct tape works! Now if you had asked all of the advocates of duct-taping warts to show you the math, you'd have likely gotten a lot of dumb looks. (Like you're getting from me) [Embarrassed]

! I am the messenger, not the scientist. I have found a system that works, and works well. If you're the scientist that you claim to be it should be a cake walk for you to prove to me and everyone else why it works.

You ask why the Audette method isn't well known--but it is in fact well known, and has been for years. And it works about half of the time--it just doesn't work as well as the OCW method.

My method is relatively new. I've been sharing the method with a few fellow shooters, and noting excellent performance in a variety of rifles from identical load recipes arrived at via my method. This began less than one year ago.

You seem to be ignoring what Denton has said for some reason...

So again, it makes not a whit of difference whether Hotcore or I can back any claims with math or science. If something works, it works. We can bring the egg-heads in later to tell us why it works. Know too that the egg-heads maintained for years that bumble-bees could not fly. But that was of course news to the bees! [Smile]

You are in the precarious postion of arguing that bumble bees can't fly because no one has shown you the math! [Smile]

Anyway, in the inimatable words of Bill O'Reilly, I'm going to give you the last word here... Unfortunately we aren't about to solve anything with the continued rhetoric. [Frown]

Best of luck to you and yours,

Dan Newberry
green 788

24 February 2003, 10:36

<green 788>

Denton...

By the way, I completely understand the nomenclature thing regarding harmonics. My only formal training is in electronics, but that does give me some understanding of harmonics (RF frequency heterodyning, etc.)...

The barrel's main vibration is just that, a vibration.

The ensuing "quivers and quakes" then are the harmonics.

I'll be working the word "harmonic" out of my rhetoric, and working in "vibration" as I'm able...

Okay? [Smile]

Good point, well stated...

Dan

24 February 2003, 10:54

Gustavo

quote:
Originally posted by green 788:
Unfortunately, Gus, it appears that no amount of math, science, or anything else is going to convince you here. It appears that this has become some sort of a quest for you not to lose a debate...

Over the eons of human existence, there have been formulas and methods that were first noted to work, and only later scrutinized by science. Serendipity... And 99.997 percent of the time, you can bet that those who noted the usefulness of those formulas and methods were not the scientists themselves.

Did you know that for over 50 years some people have been putting a duct tape patch over their warts because someone, somewhere noted that the duct tape patch totally removed the wart faster and more efficiently than any medicines on the market? And just last month I heard of the scientific study on that matter, which did in fact conclude that the duct tape works! Now if you had asked all of the advocates of duct-taping warts to show you the math, you'd have likely gotten a lot of dumb looks. (Like you're getting from me) ! I am the messenger, not the scientist. I have found a system that works, and works well. If you're the scientist that you claim to be it should be a cake walk for you to prove to me and everyone else why it works.

You ask why the Audette method isn't well known--but it is in fact well known, and has been for years. And it works about half of the time--it just doesn't work as well as the OCW method.

My method is relatively new. I've been sharing the method with a few fellow shooters, and noting excellent performance in a variety of rifles from identical load recipes arrived at via my method. This began less than one year ago.

You seem to be ignoring what Denton has said for some reason...

So again, it makes not a whit of difference whether Hotcore or I can back any claims with math or science. If something works, it works. We can bring the egg-heads in later to tell us why it works. Know too that the egg-heads maintained for years that bumble-bees could not fly. But that was of course news to the bees! You are in the precarious postion of arguing that bumble bees can't fly because no one has shown you the math!

Anyway, in the inimatable words of Bill O'Reilly, I'm going to give you the last word here... Unfortunately we aren't about to solve anything with the continued rhetoric.

Best of luck to you and yours,

Dan Newberry
green 788

Dan,

First of all... this is not a personal crusade against your idea. On the contrary! but I cannot take offense on a free basis, especially when I tried to condcut a reasonable debate.

I did not questioned Denton, becasue he offered a model, and until I see it, I had no comments whatsoever.

Let me make my point :

Many times before I said that I appreciated your work, becuase it's interesting, but your response is always the same... I understand that you have no means to prove it in a scientific manner, but don't descredit science because you don't like it.

The problem here, as I see it is that you like to claim, even mixing concepts not fully understood, like harmonics and the OCW...

Iï¿½m very interested to see someday a hard-working method, but try to listen others instead of beat them. [Wink]

Of course, I have no intention to develop such model, because people like HotCore are so good that I prefer to wait and see. [Big Grin]

Keep up the good work. Again, don't fear debate if you really want to improve. Otherwise, stop claiming.

Best regards,

24 February 2003, 14:04

Hot Core

quote:
Originally posted by Gustavo:
1) In other words, verifiable evidence.
2) HotCore, where did you learn your Engineering ??
3) But, please STOP claiming!!!!!!

Hey Gus,
1. I gave you a two ways where you can verify the excellent Cerighton Audette Method for yourself. If you choose not to avail yourself of those opportunities, so be it.

I've got binders full of data developed using this method over four decades on many, many firearms and am very happy with it, so I've proved it to myself.

2) Actually, I have two Engineering Degrees. One from UL and one from UK.

3) Feel free to "scroll on past" any posts you see with my name on them. But, I'll continue to post whenever I desire to.

[ 02-24-2003, 05:14: Message edited by: Hot Core ]

25 February 2003, 09:58

Brent Moffitt

I have some targets I'll post pics of tomarrow on a test I did the other day. You all can tell me what you think. I comprimised and shot them at 200 yards. There is definatly some POI shift. I'll let you guys give your thoughts on it, I'm not sure what to think yet.

Later,

25 February 2003, 01:09

<green 788>

Brent,

Looking forward to seeing the targets... If the wind was dead calm, the information should be useful...

Begin your own thread if you're so inclined...

Dan

25 February 2003, 09:53

pertinax

I'll chime in here too: I'm a physicist by degree, though I don't pretend to be an expert in materials science. But I do know a good bit about wave propagation and harmonics-- and also about modeling the real world.

That said, I think some of you folks are over-simplifying the situation with respect to the barrel oscillation. This isn't a "rung bell" situation! There is no single impulse driving the vibration. Rather, the bullet moving down the barrel acts as a continuous influence on the oscillation. I won't even hazard a guess as to what its effects are, but there's every reason to expect that this situation is NOT like a simple fixed-at-one end vibrating rod.

Pertinax

25 February 2003, 11:21

Brent Moffitt

I'll post the targets on another thread. [Wink]

25 February 2003, 11:28

Gustavo

quote:
Originally posted by pertinax:
I'll chime in here too: I'm a physicist by degree, though I don't pretend to be an expert in materials science. But I do know a good bit about wave propagation and harmonics-- and also about modeling the real world.

That said, I think some of you folks are over-simplifying the situation with respect to the barrel oscillation. This isn't a "rung bell" situation! There is no single impulse driving the vibration. Rather, the bullet moving down the barrel acts as a continuous influence on the oscillation. I won't even hazard a guess as to what its effects are, but there's every reason to expect that this situation is NOT like a simple fixed-at-one end vibrating rod.

Pertinax

At least!!! some words of wisdom !!! [Big Grin]

25 February 2003, 17:56

<green 788>

Pertinax,

You're right, of course... I'm corrosponding with an engineer via email who has taken an interest in OCW load development, and he too has said as much.

There have been some pretty well documented studies that show that the normal state of the muzzle is a figure "8", flattened to appear as the symbol for infinity.
As Denton mentioned, the muzzle's tendency would be to vibrate in an elliptical pattern. But add to that the twisting action being imparted by the bullet moving through the riflings, and you get the "8" pattern at the muzzle--in most cases it seems.

With a good load, the behavior of the barrel from shot to shot will be basically the same. Would you concede this?

So, if you have a load that is going to send the barrel through the same oscillation pattern for every shot, the liklihood of the shots exiting the muzzle in the same place is pretty high.

The OCW load development method seeks first to identify the powder charge range that seems capable of inducing the same vibration pattern, and then to "depth tune" the load so that the bullets exit on a friendly node of this vibration pattern.

Please continue with your thoughts if you have time...

Take care,

Dan

26 February 2003, 01:52

denton

Pertinax, it's good to see another physicist on the board. That is also my base degree. But my work these days is mostly in industrial statistics.

Of course, practically any model involves some simplification. The test of a model is this: Does it help you understand the situation, and does it produce useful information?

I think Dan is doing exactly what he should be doing. He is publishing his work, and getting other people to experiment with his method. If the method holds up in most cases, it's a useful model. It doesn't even have to hold 100% true in all cases to be useful. Many of the successful models we routinely work with are approximations.

The general idea of getting your bullets to exit during the slow-moving part of the arc is so well established as to make further discussion pointless. Does anyone seriously believe that you can improve accuracy by having bullets exit during the fast moving part of the arc? Get a grip!

Suggesting that there is something wrong with the every Nth item randomization is absurd beyond belief. This principle is so well established that you might as well try to disprove Ohm's Law. The definitive text on the subject is Box, Hunter and Hunter, if you doubt me. Deming also had some good sections on this in "Some Theory of Sampling", which, I'm afraid, is deadly dull reading.

Trying to establish a test of "spreads" as being more useful as a way of finding the "sweet spot" that a test of "means" would be an accomplishment that several generations of statisticians have failed to do. That is surely a fruitless thing to debate.

Asserting that the "robust" point of the arc, the minimum speed part of the arc, and the smallest group part of the arc are not very, very close to the same point is to deny basics that any competent Sophomore physics student can demonstrate. Read the Resnick and Halliday sections on Mechanics if you like.

So instead of arguing about who's right, let's get on with what's right. If you have data, let it speak. If you can demonstrate a better method, bring it on. That's what this forum is about. Calling names, riduculing, or demeaning others, etc. is strictly bush league stuff. You have to go at this with the attitude that if someone proves you wrong, it is cause for celebration, because you can now abandon a less useful model in favor of a more useful model, and you are better off.

26 February 2003, 05:44

pertinax

Green 788,

I'm not challenging the vibration / best-group-occurs-at-a-node wisdom. That's all undoubtedly true. But I will say I'm skeptical that a single load will group well in most (or all) guns. That seems unlikely, based on the differences known to exist between barrels. I have no evidence to back this though, and won't pretend otherwise. I'm willing to try some of your OCW combinations, but I'm not sure if my shooting ability (or guns) is sufficient to differentiate between an "OK" load, and a really good one.

I am a scientist in the true sense of the word. Evidence convinces me. This is good, healthy debate. And I'm always happy to see my favorite hobby being placed on a more scientific footing. So keep it up guys.

Pertinax

26 February 2003, 05:58

Gustavo

quote:
Originally posted by pertinax:
Green 788,

I'm not challenging the vibration / best-group-occurs-at-a-node wisdom. That's all undoubtedly true. But I will say I'm skeptical that a single load will group well in most (or all) guns. That seems unlikely, based on the differences known to exist between barrels. I have no evidence to back this though, and won't pretend otherwise. I'm willing to try some of your OCW combinations, but I'm not sure if my shooting ability (or guns) is sufficient to differentiate between an "OK" load, and a really good one.

I am a scientist in the true sense of the word. Evidence convinces me. This is good, healthy debate. And I'm always happy to see my favorite hobby being placed on a more scientific footing. So keep it up guys.

Pertinax

Well... seems we are at least two... at last!!

The search for true is full of rocks... but only the ones with enough knowledge, effort and patience and a real interest will know how to avoid them.

Try again. [Razz]

26 February 2003, 06:01

<green 788>

Pertinax,

Check this link and tell me what you think... [Smile]

http://216.219.200.59/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic&f=1&t=001381

Glad to have you involved here...

Dan

26 February 2003, 06:47

R-WEST

Gus - Maybe Dan's method doesn't make sense to you because you're upside down, down there in Argentina? [Smile]

Back to the original topic - I have to believe Dan's OCW system is close to being right on, how else to explain why the loads he's come up with can work so well in so many different rifles? I can verify that the same loads he's come up with as "optimum" for the 270 and 30-06 are, in fact, the same loads that I've come up with, through much trial and error, as optimum in MY 270's, 308's and 30-06's, as well as numerous other guys I've corresponded with.

I look forward to testing his 243 OCW load (who'da ever thunk I3031 would be an optimum powder in the 243?) if the snow ever melts off my range.

R-WEST
( [Frown]

average snow cover on R-WEST's range as of 2-25-03=8.5 feet [Frown]

)

[ 02-25-2003, 21:49: Message edited by: R-WEST ]

26 February 2003, 07:41

<green 788>

Thanks, RWest... I think you'll like the 3031 in your .243 for sure. All three of mine shoot that powder exceedingly well, and they all group the 39.8 grain charge with 58 to 60 grain bullets into 1/2" groups, with occasional deviations toward 3/4" in the one that's needing a new barrel soon.

Take care, and thanks for the commentary,

Dan

26 February 2003, 07:59

Gustavo

[QUOTE]Originally posted by R-WEST:
[QB]Gus - Maybe Dan's method doesn't make sense to you because you're upside down, down there in Argentina? [Smile]

Who knows ?? maybe you got a point !! [Big Grin]

02 March 2003, 08:18

<wksinatl>

DAMN, you guys are making my head hurt!!! [Big Grin]

Keith

02 March 2003, 10:01

Turok

quote:
ï¿½Now that you have the knowledge to understand why the never improved upon Audette Method works, all you have to do is go shoot lots of firearms creating many groups to verify what you already know is true.ï¿½

You seem to be extremely anti-evolutionary there HotCore. If everything that was used in the old days was so great, then we would never had the need to move on to anything else.

I also see that youï¿½re still up to your old tricks of debate i.e. attempting to cast a bad light on people by changing their names, or showing disrespect via deliberately spelling their names wrong, i.e. ï¿½Rookiegreenï¿½s MUC Load Methodï¿½, asserting claims to a ï¿½higher powerï¿½ i.e "never improved upon Audette Method", or appealing to claims of time and 'knowledge' i.e. ï¿½in use by knowledgeable reloaders for many yearsï¿½ etc. In the latter you come off as if to say that a half-wit developed Danï¿½s method, therefore, there is no need to try testing it, or even developing a database that shows the validity one way or the other. How about bringing the debate up to a more scientific level?

If you were half of the scientist that you claim to be, I believe you would TRY the method you decry and show statistics as to why it is faulty. After all the whole idea behind science is to find the truth through testing. If you find something contrary to your hypothesis, then you change your tune. You do not deny it in the face of your findings.

Also, in not trying Danï¿½s method before you decry it, you fall into an extremely hypocritical position with heavy overtones of double standards when you hold people to these levels in debating CHE/PRE.

Iï¿½ll be blunt here, have you tried Danï¿½s method? Do you have statï¿½s from these tests to prove/disprove its validity? Claiming that you have binders full of info on how well the Audette Method works does nothing to disprove Danï¿½s method. Iï¿½ll agree that it does provide us with another method, but again, it does nothing do disprove anything. So far, we have seen a number of targets from people who have actually tried the method and they seem to hold up Danï¿½s claims. For whatever reason (Iï¿½m no scientist or statistician ï¿½ I prefer archaeology [Smile]

) the method seems to work.

The whole debate brings to mind Einsteinï¿½s response to being told that a hundred scientists were working to disprove his theory of relativity, in which he replied with something to the effect of, ï¿½If I am wrong, then wouldnï¿½t it only take one?ï¿½

Turok