Optimum barrel time: great theory or bunk?

[Bbracken667]

There's no such thing as a "node".

Santa isn't real either.

Get over it.

In harmonics and vibrational effects there most certainly are nodes. We discovered that sometime after the wheel. Before quantum physics. Ever play a stringed instrument?
It’s a fact, it’s science, it is not in question.

https://www.researchgate.net/publication/310754444_Dynamic_Analysis_of_Steel_Platforms_When_Subjected_to_Mechanical_Equipment-Induced_Vibrations

Free and Forced Vibration Analysis of an Infilled Steel Frame: Experimental, Numerical, and Analytical Methods

Structural frames with masonry infill panels make up a significant portion of the buildings constructed in earthquake-prone areas prior to the developing of the seismic design standards. In this paper, the effects of masonry panels on the vibration response of an infilled steel-frame building...

www.hindawi.com

 

[918v]

You people need to just stop redefining reloading terms. We all know what nodes are and that nodes exist.

 

[Baron23]

velocity vs grains of powder isn't helpful either.
No real flat spots.

What a shock...add more propellant and the projectile speeds up. Amazing stuff that physics and chemistry! ;-) haha

 

[kthomas]

In harmonics and vibrational effects there most certainly are nodes. We discovered that sometime after the wheel. Before quantum physics. Ever play a stringed instrument?
It’s a fact, it’s science, it is not in question.

https://www.researchgate.net/publication/310754444_Dynamic_Analysis_of_Steel_Platforms_When_Subjected_to_Mechanical_Equipment-Induced_Vibrations

Free and Forced Vibration Analysis of an Infilled Steel Frame: Experimental, Numerical, and Analytical Methods

Structural frames with masonry infill panels make up a significant portion of the buildings constructed in earthquake-prone areas prior to the developing of the seismic design standards. In this paper, the effects of masonry panels on the vibration response of an infilled steel-frame building...

www.hindawi.com

It's undebatable that there are harmonic and vibrational effects occuring.

What is debatable is what effects these factors have on precision, and if methods and devices like OBT and tuners are as effective in utilizing these effects to increase precision as some proclaim. Especially given how very weak the datasets are to make such determinant conclusions.

 

[CK1.0]

It's hilarious when random guys in a reloading forum pompously talk about harmonics like they actually know anything.

Especially when, if they wanted to pontificate, they should be discussing shockwaves, since most of the nonsense guys talk about in defense of tuners and harmonics as it pertains to "nodes" happens after the projectile has already left the barrel.

High-speed Imaging of Shock Waves, Explosions and Gunshots

New digital video technology, combined with some classic imaging techniques, reveals shock waves as never before

www.americanscientist.org

 

[Bbracken667]

It's undebatable that there are harmonic and vibrational effects occuring.

What is debatable is what effects these factors have on precision, and if methods and devices like OBT and tuners are as effective in utilizing these effects to increase precision as some proclaim. Especially given how very weak the datasets are to make such determinant conclusions.

Fair enough. What does changing the seating depth do? What do barrel tuners do?
I am sorry, but the existence of nodes is not debatable but what is is how to best take advantage of them and how to reliably predict the effect.

The fact of quantum effects are not debatable but the application is still being explored. Some quantum effects, specially the dual nature of light as wave and particle is mind blowing. It exists, just as harmonics and vibrational effects in steel. Not debatable.

Sorry, part of this reply is directed at the individual who claimed nodes do not exist.

 

[4O6shootist]

A powder node that holds a small velocity spread means nothing if at distance that speed is in a velocity band that holds tight vertical. A bullet in the right velocity band, could be es of 30, will hold tight vertical at distance, the thing is, find that tight powder velocity spread in the powder, then tune seating depth to find the best accuracy. What are you doing here? Changing that seating depth changes the timing of where it exits the muzzle in microseconds making it all line up. Essentially your tining bullet exit with barrel harmonic. Optimal barrel time, but OBT on GRT isn't right all the time, prob less than half the time. GRT says barrel length doesn't affect OBT, but I've found my 28" barrels always shoot the best 20-40 fps faster than GRT calcs even with the barrel length iodated. I just do shit my own way now, and it works, no OBT, no Sateelee, no optimal charge weight.

 

[kthomas]

Fair enough. What does changing the seating depth do? What do barrel tuners do?
I am sorry, but the existence of nodes is not debatable but what is is how to best take advantage of them and how to reliably predict the effect.

The fact of quantum effects are not debatable but the application is still being explored. Some quantum effects, specially the dual nature of light as wave and particle is mind blowing. It exists, just as harmonics and vibrational effects in steel. Not debatable.

Sorry, part of this reply is directed at the individual who claimed nodes do not exist.

The more I reload, shoot and test, the less I am personally convinced of any precision "nodes".

I don't spend any time doing bullet depth seating tests anymore, and I don't chase lands. And I'm producing better shooting ammo than I ever have.

And I'm extremely skeptical of claims that OBT and tuners can take advantage of any harmonic effects to increase precision.

 

[CK1.0]

When is the last time anyone's heard someone say "Gee, this load I've got reliably gets me single-digit SDs and an ES in the low teens, but it just doesn't group or hold vertical downrange" ..?

Probably never.

It's not because they're in a "node", it's because they load really consistent ammo.

I don't have to be the great Zoltar to know that if one was to put 30-something grains of Varget into a 6mm case with a 35-40deg shoulder, dropping every powder charge to the kernel, seating every bullet to within .001-.002" of each other CBTO, 20-30 thou off the lands, that they'll be in a "node"...

...but I know it'll shoot, and sooner or later some fudd will tell them it's that.

 

[4O6shootist]

When is the last time anyone's heard someone say "Gee, this load I've got reliably gets me single-digit SDs and an ES in the low teens, but it just doesn't group or hold vertical downrange" ..?

Probably never.

It's not because they're in a "node", it's because they load really consistent ammo.

I don't have to be the great Zoltar to know that if one was to put 30-something grains of Varget into a 6mm case with a 35-40deg shoulder, dropping every powder charge to the kernel, seating every bullet to within .001-.002" of each other CBTO, 20-30 thou off the lands, that they'll be in a "node"...

...but I know it'll shoot, and sooner or later some fudd will tell them it's that.

A br variant isn't much of example, you can put 31gr of dogshit into one and it'll shoot half minute. I know a handful of shooters running the same exact load for 3-4 dasher barrels in a row, they never tweak powder or depth. That theory doesn't work on a prc, Saum, or Norma case.

1k yard benchrest shooters, they are arguably the best rifle tuner/reloaders in the world. They find a velocity window that holds tightest vertical at distance. They then tune the charge, nk tension, seating depth and primer type/depth for optimum micro accuracy/smallest ES/SD possible. I know that's going into the weeds, but their starting point is finding the velocity the bullet tells you it likes are distance.

 

[kthomas]

Why would a BR variant be immune to the laws of harmonics that people prescribe to all other cartridges?

 

[brianf]

In harmonics and vibrational effects there most certainly are nodes. We discovered that sometime after the wheel. Before quantum physics. Ever play a stringed instrument?
It’s a fact, it’s science, it is not in question.

https://www.researchgate.net/publication/310754444_Dynamic_Analysis_of_Steel_Platforms_When_Subjected_to_Mechanical_Equipment-Induced_Vibrations

Free and Forced Vibration Analysis of an Infilled Steel Frame: Experimental, Numerical, and Analytical Methods

Structural frames with masonry infill panels make up a significant portion of the buildings constructed in earthquake-prone areas prior to the developing of the seismic design standards. In this paper, the effects of masonry panels on the vibration response of an infilled steel-frame building...

www.hindawi.com

A out of tune guitar doesn’t magically change “it’s tune”. It’s just not hitting the desired note. But the note it does hit is consistent.

As for vibration and nodes your taking a huge step.

There is no imperial data linking vibration/barrel whip/bore bulge and a list of other things, some discussed on this thread to possible nodes

There is tons of data yet it’s not correlated.

Is it one or is it all possible variables meet at the Goldilocks zone /node.

And if all meet perfectly how can a node be wide? A million variables all of a sudden line up like the planets for a month not a few nights.

If we believe in nodes then we have to disagree with newton laws of motion…im betting on newton.

 

[4O6shootist]

Why would a BR variant be immune to the laws of harmonics that people prescribe to all other cartridges?

Because they're magic, that's why we shoot them! Jokes aside, I think it's due to the reduced case capacity causing less of a shockwave resonance vibration in the barrel to deal with. Just a theory.

 

[kthomas]

Because they're magic, that's why we shoot them! Jokes aside, I think it's due to the reduced case capacity causing less of a shockwave resonance vibration in the barrel to deal with. Just a theory.

Would the same not be true then for any cartridge that has a reduced capacity? Like a .223?

 

[4O6shootist]

Would the same not be true then for any cartridge that has a reduced capacity? Like a .223?

Isn't a 223 with lapua brass and quality components very easy to make shoot? It's the shit milspec brass that everyone plays with that's the problem. The king of 300y benchrest is the 6ppc case, even smaller than BR. Lapua 6.5 grendel on a quality bolt gun, excellent accuracy. The problem is, rarely do you see guys building these small cases on a custom action by a competent smith anymore due to the ballistics of the low velocity with heavy high bc bullets. 300y and in benchrest is still dominated by flat base bullets idk why but they shoot smaller than boat tails at shorter ranges.

You have to compare apples to apples, we run lapua and alpha brass for it's consistency, can't get a 6br, bra or dasher on a cheap factory offering, so they all custom or highest end production(think gap ppr or mpa production), using excellent brass, yeah it's gonna shoot!

 

[kthomas]

A out of tune guitar doesn’t magically change “it’s tune”. It’s just not hitting the desired note. But the note it does hit is consistent.

As for vibration and nodes your taking a huge step.

There is no imperial data linking vibration/barrel whip/bore bulge and a list of other things, some discussed on this thread to possible nodes

There is tons of data yet it’s not correlated.

Is it one or is it all possible variables meet at the Goldilocks zone /node.

And if all meet perfectly how can a node be wide? A million variables all of a sudden line up like the planets for a month not a few nights.

If we believe in nodes then we have to disagree with newton laws of motion…im betting on newton.

And no one can adequately explain or describe the mechanisms that produce such magical "nodes".

The excuse that they exist simply because extremely limited testing and weak data sets say so is not a very compelling argument.

 

[kthomas]

Isn't a 223 with lapua brass and quality components very easy to make shoot? It's the shit milspec brass that everyone plays with that's the problem.

I would extend that argument to most any cartridge - if you use high quality components and reloading gear with good consistent reloading practices. And of course a good quality barrel, chamber and chamber design.

I think people have a tendency to prescribe inherent precision qualities to BR variants because they are much easier to shoot than say a 6.5 Creedmoor. Or a PRC. Or .308. Or a Norma. Those small (to big) differences in recoil makes a big difference when trying to consistently drive the gun - and no one wants to blame the shooter (i.e. themselves).

It's a common flaw to blame equipment over our own skillsets (or lack thereof). People do it in every sport, and reloading/shooting is no exception. What you can get away with when shooting a 6BRA will result in devastatingly bad groups with a .308.

What I don't buy is that there is a magical terminal velocity. Or that a specific powder charge produces a uniquely precise "node". Or that a specific tuner setting will make your ammo all of a sudden shoot a 1/2 MOA better.

 

[chevy_man]

I've yet to be convinced that there's a magical frequency that your barrel should resonate at for optimum precision.

I have seen barrels shoot a random large group at certain velocities even with tiny SD and ES.

Theory is that the barrel will resonate no matter what we do. If you time the bullet to leave the barrel when the muzzle is at the top or bottom of a wave it has a dwell time while it switches direction. This leads to tiny groups, unless you have large SD/ES that shows as vertical stringing.


So if you can predict the frequency and time for the bullet to travel down the bore, you can predict how to load to time it correctly to hit that dwell.


I also attribute this to why I have seen very heavy barrels shoot a very wide range of loads, while pencil thin barrels I've had to settle for tiny nodes.

 

[4O6shootist]

@kthomas I don't buy tuners being magic, but they have the potential to make good load slightly better, other setting on the tuner will make them worse. I have rifles with tuners, and some without. I still do my normal process of loading with tuner at zero, then see if the tuner repeatedly will refine my load to a better result. I have also taken and done a powder test to find small es near the velocity where a given cartridge/bullet weight(think bra/dasher with 108s at 2850) picked a starting seating depth of say -40k, and used the tuner to take a 0.7" load and turn it into consistent 0.4" load. At the end of the day, if you missed because your rifle shot 0.7moa, not 0.4 moa, it's still on the shooter because the groups quite a bit smaller than the target. When I miss, I blame myself, not the gun, always, because I am in control of every aspect of that weapon, the raw accuracy and the consistency of the precision operating it.

 

[kthomas]

I have seen barrels shoot a random large group at certain velocities even with tiny SD and ES.

Theory is that the barrel will resonate no matter what we do. If you time the bullet to leave the barrel when the muzzle is at the top or bottom of a wave it has a dwell time while it switches direction. This leads to tiny groups, unless you have large SD/ES that shows as vertical stringing.


So if you can predict the frequency and time for the bullet to travel down the bore, you can predict how to load to time it correctly to hit that dwell.


I also attribute this to why I have seen very heavy barrels shoot a very wide range of loads, while pencil thin barrels I've had to settle for tiny nodes.

With how many factors that are involved in reloading and shooting, and how many of these factors have hard limitations on the degree of precision in which we can hold, I don't think anyone is reliably finding a few millisecond window of "dwell".

And besides, that tiny window of "dwell" will change every day - changes in atmospheric conditions will be shifting that "dwell" window. I think it's a fallacy if anyone thinks that:

1. They are controlling variables to such a tight degree to perfectly and reliably time this "dwell" window

AND

2. That this "dwell" window stays the same throughout all conditions you shoot in

 

[Huskydriver]

It's kinda funny I was chatting with a new shooter the other day about my load dev.... he was a little shocked all I do is pick a powder charge to see how fast it is and seat 20 tho off....if the velocity I want is there I'm done...

0 empirical evidence or data to offer to the discussion but anecdotally over the course of dozens of barrels and different chamberings I too am skeptical of most "traditional" reloading dogma and don't believe in nodes

 

[kthomas]

@kthomas I don't buy tuners being magic, but they have the potential to make good load slightly better, other setting on the tuner will make them worse. I have rifles with tuners, and some without. I still do my normal process of loading with tuner at zero, then see if the tuner repeatedly will refine my load to a better result. I have also taken and done a powder test to find small es near the velocity where a given cartridge/bullet weight(think bra/dasher with 108s at 2850) picked a starting seating depth of say -40k, and used the tuner to take a 0.7" load and turn it into consistent 0.4" load. At the end of the day, if you missed because your rifle shot 0.7moa, not 0.4 moa, it's still on the shooter because the groups quite a bit smaller than the target. When I miss, I blame myself, not the gun, always, because I am in control of every aspect of that weapon, the raw accuracy and the consistency of the precision operating it.

I know that you can change POA/POI with a change in weight in the end of a barrel, and I know that sometimes adding weight on the barrel (like a suppressor) can help improve things.

But I personally don't buy that moving a small weight on the end of your barrel by mere microns will result in a meaningful increase in precision performance. And I say this as someone who owns a couple of tuners.

At the end of the day, to each their own. If a tuner works for you, then by all means use it. I just don't buy a lot of the claims of what tuners can do.

 

[kthomas]

It's kinda funny I was chatting with a new shooter the other day about my load dev.... he was a little shocked all I do is pick a powder charge to see how fast it is and seat 20 tho off....if the velocity I want is there I'm done...

0 empirical evidence or data to offer to the discussion but anecdotally over the course of dozens of barrels and different chamberings I too am skeptical of most "traditional" reloading dogma and don't believe in nodes

The longer that I've been on this planet and the more reloading/shooting I do, the simpler my reloading process tends to become.

And my reloads have only gotten better over the years. There's an incredible amount of myth and lore to reloading, and new reloaders have to wade through a ton of bullshit about reloading...

 

[4O6shootist]

I know that you can change POA/POI with a change in weight in the end of a barrel, and I know that sometimes adding weight on the barrel (like a suppressor) can help improve things.

But I personally don't buy that moving a small weight on the end of your barrel by mere microns will result in a meaningful increase in precision performance. And I say this as someone who owns a couple of tuners.

At the end of the day, to each their own. If a tuner works for you, then by all means use it. I just don't buy a lot of the claims of what tuners can do.

I may not have enough sample size either, how many of us sit down and shoot 20x 5 shot groups, or 10x 10 shot groups on paper? Prob none, cuz that's boring and really showcases our flaws or subtracts from the ego. I mean if I put 50 round on paper and it's half minute avg, but I loaded 200 rounds, is that a half moa gun? Prob not cuz only 25% of the results will be sampled. SD potentially gets smaller or same with sample size, but es will always get larger, comparing any and all data.

 

[kthomas]

I may not have enough sample size either, how many of us sit down and shoot 20x 5 shot groups, or 10x 10 shot groups on paper? Prob none, cuz that's boring and really showcases our flaws or subtracts from the ego. I mean if I put 50 round on paper and it's half minute avg, but I loaded 200 rounds, is that a half moa gun? Prob not cuz only 25% of the results will be sampled. SD potentially gets smaller or same with sample size, but es will always get larger, comparing any and all data.

And that's the bitch to statistics and testing, and also encapsulates the average shooter's/reloader's mindset.

To perform any real adequate testing would require a lot of resources and procedures that pretty much no shooter (including myself) could be bothered with (if they even understand how to do so).

So instead, we rely on small datasets that are statistically irrelevant. From that, we try to draw conclusions from - but at the peril of drawing conclusions that don't actually exist if you were to increase the sample size and test in an appropriate manner.

I know far from everything, and I (and everyone else) still has a lot to learn about reloading and internal & external ballistics. What I do know is that a lot of what gets spread as reloading "truths" are in fact nothing of the sort. Even great shooters and reloaders seem to have a pretty limited understanding of what's actually occurring. What is crystal clear to me is that our community (in a very broad sense) has a tendency to make dispositive conclusions from data that can't actually provide those conclusions - and as such a lot of our premises around reloading are pretty flawed.

 

[Baron23]

It's hilarious when random guys in a reloading forum pompously talk about harmonics like they actually know anything.

Especially when, if they wanted to pontificate, they should be discussing shockwaves, since most of the nonsense guys talk about in defense of tuners and harmonics as it pertains to "nodes" happens after the projectile has already left the barrel.

High-speed Imaging of Shock Waves, Explosions and Gunshots

New digital video technology, combined with some classic imaging techniques, reveals shock waves as never before

www.americanscientist.org

Actually, you are misinterpreting that article to the extent to leave me almost speechless.

Shock waves...subject of that article....in the air as the bullet travels faster than the speed of sound and is part of what we would consider external ballistics. I dunno, but suspect that proper formation of this from the get go may well be why muzzle crown integrity/consistency/etc is so important.

What people are discussing here is internal ballistics and specifically the impact of rapidly expanding gas (from the powder) and a rapidly accelerating mass (with some degree of friction, linear and rotational inertia, and who knows what the fuck else) has on the actual barrel and if that is predictable enough to be controlled the instant the bullet leaves the barrel.

And people often talk about movement of the barrel as if it was a simple sine wave in the vertical axis traveling its length and I see absolutely no reason for this to be true.

I'm not convinced. On the other hand, I'm getting pretty old and ain't all that great of a shot so it probably well inside the noise as far as my shooting goes.

Cheers

 

[CK1.0]

Actually, you are misinterpreting that article to the extent to leave me almost speechless.

Shock waves...subject of that article....in the air as the bullet travels faster than the speed of sound and is part of what we would consider external ballistics. I dunno, but suspect that proper formation of this from the get go may well be why muzzle crown integrity/consistency/etc is so important.

What people are discussing here is internal ballistics and specifically the impact of rapidly expanding gas (from the powder) and a rapidly accelerating mass (with some degree of friction, linear and rotational inertia, and who knows what the fuck else) has on the actual barrel and if that is predictable enough to be controlled the instant the bullet leaves the barrel.

And people often talk about movement of the barrel as if it was a simple sine wave in the vertical axis traveling its length and I see absolutely no reason for this to be true.

I'm not convinced. On the other hand, I'm getting pretty old and ain't all that great of a shot so it probably well inside the noise as far as my shooting goes.

Cheers

I'm not misinterpreting anything. I was trying to show how little is actually known about the main thing affecting our projectiles before they are out of the barrel (shockwaves).

In the article, it literally says: "The interior ballistics of firearms cannot be observed by the methods described here, so the first visible phenomenon at the muzzle is the emergence of the bullet-driven shock wave, followed immediately by the bullet itself."

If someone wants to believe they can somehow crack the code to where they can alter the resonance of their barrel by adjusting weight/length by thousandths-of-a-percent (with a tuner), or by experimenting with slightly different charges or seating depths, to control the resulting shockwaves (that we haven't figured out how to see yet) enough to make the barrel shoot better, so be it. Sounds kind of ridiculous and a lot like a fool's errand to me.

 

[secondofangle2]

Tomorrow I’m going out to test my brand new Cheytac barrel. Different maker, twist, reamer, profile, length, freebore from my current barrel which shoots like the pic. Loads form current barrel chamber in new barrel. And this load is known for working across many barrels. I’ll let y’all know if it just plugs and plays in the new barrel.

 

[Mormegil87]

What constitutes a node? What are the parameters of a velocity/charge weight node or an accuracy node?

 

[Rio Precision Gunworks]

And yet Newton is obsolete and became so during the 19th century. Einstein surpassed him, and the whole of Quantum physics surpassed them both, essentially.
You can choose to not believe in nodes, but I will continue to believe science is smarter. Just because a phenomena is not understood does not mean it does not exist. There is no huge leap from one vibratory effect to another. Just an increase in complexities.
The whole dual slit experiment will blow your mind if you have not heard of it before. Ergo I am not arguing about something I cannot model, but I have enough science in my background, career and education to understand what is, and what is likely not. Nodal behavior in metals, particularly steel, is not in question. You may, should you choose, I no longer care. You can disavow the wheel or calculus, that’s on you. You can deny the cycles of glaciation and interglacial periods that have repeated over the last 450k years, that’s great. Again, your “belief” in facts are not required.
I am done with the arguments about what is known.
Have a great evening. I will continue with my testing and experimenting because I find it interesting. I do not find pointless arguments with Luddites interesting in the least.

For anyone with the time and interest:

You're taking a giant leap from the clear misunderstanding you have of the "enough science in your background."

Literally all this paragraph is just semi coherent mildly scientific jargon thrown together in an attempt to sound educated.

 

[brianf]

And yet Newton is obsolete and became so during the 19th century. Einstein surpassed him, and the whole of Quantum physics surpassed them both, essentially.
You can choose to not believe in nodes, but I will continue to believe science is smarter. Just because a phenomena is not understood does not mean it does not exist. There is no huge leap from one vibratory effect to another. Just an increase in complexities.
The whole dual slit experiment will blow your mind if you have not heard of it before. Ergo I am not arguing about something I cannot model, but I have enough science in my background, career and education to understand what is, and what is likely not. Nodal behavior in metals, particularly steel, is not in question. You may, should you choose, I no longer care. You can disavow the wheel or calculus, that’s on you. You can deny the cycles of glaciation and interglacial periods that have repeated over the last 450k years, that’s great. Again, your “belief” in facts are not required.
I am done with the arguments about what is known.
Have a great evening. I will continue with my testing and experimenting because I find it interesting. I do not find pointless arguments with Luddites interesting in the least.

For anyone with the time and interest:

Trying to be the smartest person in the room isn’t always the best approach.

But to each their own.

When you gave definitive confirmation about nodes I’ll pay for your ticket to prove them to Litz but we get to live feed it.

 

[Mormegil87]

Not my area of expertise nor education. Neither is chemistry, but chemical processes exist. Not being able to adequately answer questions does not establish a lack of fact.
Using calculus, calculate the levels of volume of a cylinder. See how that works?

https://www.researchgate.net/publication/349310808_Vibratory_Stress_Relief_of_Welded_Austenite_Stainless_Steel_Plates_A_Numerical_and_Experimental_Approach

So define the process. Is it one shot per charge weight for 10 charge weights? 2 shots per, for 10 weights? 3 shots over 5 weights? 5 shots per weight over 10 different charges? What is the optimal charge weight interval? Do we need need to see an ES of 10fps over 3 adjacent weights or will 15fps suffice?

See what I'm getting at? There is no defined process. Yet everyone wants to hang their hat on this theory.

If you could point me to a paper or manual, with source material sited, that says something to the effect of: To obtain the optimum accuracy you need to load to a node. A node is defined as a flat of spot in velocity of no more than 10fps of Extreme Spread over three separate charge weights, separated by a minimum of 0.3gr per charge. There must be a minimum of 3 shots per charge weight.

Then maybe I'd buy into it. But right now, it's nothing but a bunch of dudes with random processes, theories and definitions with no real data to back up those theories.

 

[brianf]

Physics Tutorial: Nodes and Anti-nodes

One characteristic of every standing wave pattern is that there are points along the medium that appear to be standing still. These points, sometimes described as points of no displacement, are referred to as nodes. There are other points along the medium that undergo vibrations between a large...

www.physicsclassroom.com

If that isn’t good enough for you, then I am locking you in the closet with the rest of the Luddites.

What about litz. I see you skipped the important part.

Proofs in the pudding.

Citing every vibration paper written is proving vibration happens in material.

Now make it correlate with specific predetermined nodes, not random acts of coincidence.

Look forward to you data.

 

[Rio Precision Gunworks]

I stated clearly I was not arguing with Luddites.
My education is my own, and exceeds high school, back before they nerfed college entrance exams.
I take it you “don’t believe” in nodal effects in steel either? As I stated above, your belief or lack thereof is not a requirement of fact. The facts exist. You can research them for yourself or just ignore them, as is the want of so many these days who ignore facts in the face of their “belief”.
Because your pickup won’t run does not invalidate the science behind internal combustion. If you believe it does, that’s your problem.
LoL

What I don't believe in is people who say "I have a science and math background" and then make several of the statements you have made which show a barely better than elementary understanding of the things you are quoting.

You're obviously wording things in a way that you can back out of if called out. "Exceeds high school" LOLOLOLOLOL.

The simple fact that you are incorrectly referencing Newton and Einsten, and then throwing in "quantum physics" is laughable and embarrassing.


Signed,

Someone with an actual education in applied mathematics.

 

[Mormegil87]

First of all: I am the OP. I posted the question, great theory or bunk. You know: The fact of vibrational nodes isnt in question for those with half a brain or the ability to use google.
The question is whether we can predict them given the complexity of the effect, the science, and the math involved. I am using GRT and will be running some tests, but have never used it before. I am getting really tired of idiots. It seems the number of believers in Idiocracy increase every year.
The number of people denying established science is disgusting. I might as well join a flat earth society group to argue with them. I have plotted course and location with a sextant but that matters not to the idiots who “believe” the earth is flat. No amount of science will change their mind. The number of people with similar philosophies is increasing yearly.
Believe stuff or not, I don’t care. I retract the question. Go live under your rock.

https://www.sciencedirect.com/science/article/pii/S2214509522002467

I didn't deny the existence of vibratory nodes. I've been playing guitar for 20 years, I know they exist.

I'm questioning the process of how to best take advantage of that phenomenon, if it's even possible. At this time, no one has empirically defined that process much less been able to prove that the process takes advantage of OBT or vibratory nodes.

But if you want to throw a temper tantrum and call people names rather than have an adult conversation, that's on you.

 

[secondofangle2]

The problem is not being addressed here and which only a PhD level, physicist or engineer could address, is what equations are appropriate to model the behavior of the particular system that we are talking about.

You can’t just say that waves exists, and therefore waves are happening in this particular milieu and they also explain the downstream variables of interest. That is completely ridiculous and wildly oversimplifies very complex subject matter.

Just because the Tacoma Narrows Bridge came apart because it hit a resonant frequency, does not mean that every single other thing that experiences a wave, no matter how big or small, with or without associated phenomena that may overwhelm the effects of the wave, has all downstream effects explained by that wave form. It is purely ridiculous.

If one of these things worked, Brian Litz would’ve already talked about it ad nausea him in his many volumes of books.

 

[kthomas]

First of all: I am the OP. I posted the question, great theory or bunk. You know: The fact of vibrational nodes isnt in question for those with half a brain or the ability to use google.
The question is whether we can predict them given the complexity of the effect, the science, and the math involved. I am using GRT and will be running some tests, but have never used it before. I am getting really tired of idiots. It seems the number of believers in Idiocracy increase every year.
The number of people denying established science is disgusting. I might as well join a flat earth society group to argue with them. I have plotted course and location with a sextant but that matters not to the idiots who “believe” the earth is flat. No amount of science will change their mind. The number of people with similar philosophies is increasing yearly.
Believe stuff or not, I don’t care. I retract the question. Go live under your rock.

There's a huge difference between recognizing harmonics and vibrational effects on materials such as metal (which do exist), versus believing that these vibrational effects can be predicted and exploited to obtain maximum precision potential in the context of ballistics.

I don't think anyone here is arguing that there isn't any sort of vibrational/harmonic effects going on with a barrel. What is being questioned and contested is the following:

1. What harmonic effects are actually occurring during the internal ballistics phase, and how does this effect external ballistics?
2. Can we predict this harmonic effects through methodology such as OBT? Are such methods valid and repeatable?
3. Can we exploit these harmonic effects to maximize precision potential?
4. Do these harmonic effects and their precise "nodes" carry over through different atmospheric conditions? Is ammo loaded within a precision node in one set of atmospheric conditions still in that node in a different set of atmospheric conditions?
5. Exactly how wide is such a "node", from the context of frequency? Do we have the ability to control all the variables to such a precise degree that we can maintain this "node" with our ammo?
6. etc, etc, etc

Just because metal vibrates doesn't mean we can exploit the phenomena to increase our precision, especially in any sort of predictable and reliable way. I don't believe anyone has a full grasp on how exactly a barrel behaves during internal ballistics, let alone how these effects play into external ballistics and our ability to predictably and reliably exploit this.

 

[brianf]

There's a huge difference between recognizing harmonics and vibrational effects on materials such as metal (which do exist), versus believing that these vibrational effects can be predicted and exploited to obtain maximum precision potential in the context of ballistics.

I don't think anyone here is arguing that there isn't any sort of vibrational/harmonic effects going on with a barrel. What is being questioned and contested is the following:

1. What harmonic effects are actually occurring during the internal ballistics phase, and how does this effect external ballistics?
2. Can we predict this harmonic effects through methodology such as OBT? Are such methods valid and repeatable?
3. Can we exploit these harmonic effects to maximize precision potential?
4. Do these harmonic effects and their precise "nodes" carry over through different atmospheric conditions? Is ammo loaded within a precision node in one set of atmospheric conditions still in that node in a different set of atmospheric conditions?
5. Exactly how wide is such a "node", from the context of frequency? Do we have the ability to control all the variables to such a precise degree that we can maintain this "node" with our ammo?
6. etc, etc, etc

Just because metal vibrates doesn't mean we can exploit the phenomena to increase our precision, especially in any sort of predictable and reliable way. I don't believe anyone has a full grasp on how exactly a barrel behaves during internal ballistics, let alone how these effects play into external ballistics and our ability to predictably and reliably exploit this.

You aren’t educated enough to understand…it’s above us public school kids

 

[kthomas]

You aren’t educated enough to understand…it’s above us public school kids

Yeah apparently I may as well be in a cave somewhere smashing rocks together...

 

[brianf]

Yeah apparently I may as well be in a cave somewhere smashing rocks together...

Do they vibrate the same every time you hit them together?

Might be some good info I can use when loading

 

[brianf]

Apparently you didn’t read my last message. Or are incapable of reading comprehension beyond that of a 4th grader.
Read it again. I am done with idiots.

I have and it’s a pile of back peddling jargon.

Once you were questioned you became defensive and are now backing away.

Nothing wrong with having a discussion or debate but speaking in absolutes, then name calling, now backing away.

It’s a common theme with certain types of people.

 

[brianf]

I just had to
One of my favorite movies

but im.smart godfatger - Google Search

 

[supercorndogs]

There's a huge difference between recognizing harmonics and vibrational effects on materials such as metal (which do exist), versus believing that these vibrational effects can be predicted and exploited to obtain maximum precision potential in the context of ballistics.

I don't think anyone here is arguing that there isn't any sort of vibrational/harmonic effects going on with a barrel. What is being questioned and contested is the following:

1. What harmonic effects are actually occurring during the internal ballistics phase, and how does this effect external ballistics?
2. Can we predict this harmonic effects through methodology such as OBT? Are such methods valid and repeatable?
3. Can we exploit these harmonic effects to maximize precision potential?
4. Do these harmonic effects and their precise "nodes" carry over through different atmospheric conditions? Is ammo loaded within a precision node in one set of atmospheric conditions still in that node in a different set of atmospheric conditions?
5. Exactly how wide is such a "node", from the context of frequency? Do we have the ability to control all the variables to such a precise degree that we can maintain this "node" with our ammo?
6. etc, etc, etc

Just because metal vibrates doesn't mean we can exploit the phenomena to increase our precision, especially in any sort of predictable and reliable way. I don't believe anyone has a full grasp on how exactly a barrel behaves during internal ballistics, let alone how these effects play into external ballistics and our ability to predictably and reliably exploit this.

What makes one powder charge shoot better than another?

What makes one charge have a different POI than another?

 

[kthomas]

What makes one powder charge shoot better than another?

What makes one charge have a different POI than another?

I'm not convinced that particular powder charges shoot better than others, especially over multiple days and conditions.

I think it would be an eye opening exercise for most to map out different powder charges and how they shoot (group size, POI, ES/SD) over multiple days and conditions.

What may appear to be dispositively the best charge weight on one day may look relatively mediocre the next, and vice versa...

 

[Dstoenner]

I think people have a tendency to prescribe inherent precision qualities to BR variants because they are much easier to shoot than say a 6.5 Creedmoor. Or a PRC. Or .308. Or a Norma. Those small (to big) differences in recoil makes a big difference when trying to consistently drive the gun - and no one wants to blame the shooter (i.e. themselves).

Brian Litz in his latest book even derives a formula for inherent accuracy of any rifle and weight and recoil are central to the equation.

David

 

[jthor]

I certainly believe in OBT. Excluding my experiences reloading, there has been several times where I taken a shooters good load and rifle data put it into QL or GRT and it has dang near lined up with an OBT node.

 

[secondofangle2]

Fooled by randomness again?

 

[Rio Precision Gunworks]

Something everyone always overlooks in the loading forums.....

Almost no one has a loading method that doesn't work. You can read through loading forums all over the internet and see 20 or more different methods. Some of those methods are even basically just made up because someone didn't full understand the method they were trying to replicate.

Many people mix and match things from multiple methods by accident or on purpose.


When all of these methods, even the ones that are inadvertent, work.....that's a huge problem for anyone attempting to claim their method works because of XYZ reasons.

A requirement for a method to be valid or superior to other methods is that other methods produce lesser results and some methods produce utter trash.


What this actually means is that most things people think matter, actually don't matter that much, if at all. Most people are making good ammo in spite of their loading method, not because of it.



This is how you end up with people actually believing they have figured out in their back yard what a literal rocket scientist with access to proper testing equipment hasn't been able to prove or disprove.

 

[Mormegil87]

^^^ this.

 

[supercorndogs]

I'm not convinced that particular powder charges shoot better than others, especially over multiple days and conditions.

I think it would be an eye opening exercise for most to map out different powder charges and how they shoot (group size, POI, ES/SD) over multiple days and conditions.

What may appear to be dispositively the best charge weight on one day may look relatively mediocre the next, and vice versa...

Why do they accuracy test when making loads for factory ammo?


You skipped the question about diffrent powder charges shooting to a diffrent POI.

Dont you think it's kind of ironic you have come to these conclusions based on your small samples. Vs millions of rounds fired in load development and competition fired by thouasands of people over the decades.

I think some guys have gotten way off in the weeds thinking not being able to decern the difference meaning there isn't one. And ignoring that it could be a resolution problem.