Positive compensation and its explanations .

Let's not worry about what has been posted as Tim can explain thar let's just keep going.

If we take a barrel blank and hang the chamber end from a string letting the muzzle point to the ground we can ring the barrel with a small wrench hammer or screwdriver and listen to it vibrate.
We can then take a finger or 2 and run it along the muzzle looking for that node we can see in both the welding rod or the fishing pole.
It will feel like nothing is vibrating while we can feel the barrel vibrating on both sides of that point.
We can mark that point with a sharpie and do the test multiple times to confirm it is there.
For the average barrel we would see in this forum that node would be roughly 2.5-3 inches back from the muzzle.
To the average shooter it would resemble a teeter tottering.
Are we still good?

I understand everything you are saying.

None of the testing provided so far can demonstrate this phenomena.
 
Okay so we can test and find that the node of the barrel is roughly 2.75 inches behind the muzzle.
We also know that adding weight will dampen the amplitude of the barrel which broadens the area under the curve.
So the added weight makes the teeter tottering look flatter.
In our original testing of the welding rod or fishing pole no matter how hard we shook it the standing wave or node never changed its position just it's amplitude.
The flattest we can get the muzzle is by adding weight out in front of the muzzle which moves the node out further.
We can test that by adding length to the welding rod or taping a pencil to the tip of the fishing pole.
Are you still with me?

If yes we can next calculate the weight needed to move the node to the muzzle.
We do that by calculating the weight of the barrel past the node. We know the length is 2.75 inches and let's make the barrel 30 caliber at 1.25 straight cylinder. The weight is then multiplied by 1.5 and we get 1.3 pounds or 20.8 ounces of weight.
We now add 20 ounces to the muzzle 2.75 inches out in front to move the node all the way to the muzzle.
This is as flat as we can make the sine wave or teeter totter.
So your typical 375 cheytac barrel at 1.125 inches needs a tuner around 16-20 ounces and almost 3 inches in front of the muzzle.
This will give the most compensation possible.
 
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The standing waves you refer to have not developed by the time the bullet has left the barrel. The transient forced response does not take the form of a repeating sine wave.

For a rifle with a CG below the bore centerline the dominant feature of the forced response is a single low-high-low curve with bullet exit in the vicinity of the peak. Shifting exit time relative to the peak of that curve could conceivably produce a compensation effect, but a difference in internal ballistics leading to a change in exit time also slightly changes the curve itself.

Some of Tim's waterline targets sweeping a large range of charges appear to show that behavior. That said, the waterline test is complicated by the fact that, ignoring throwoff/aero jump, it still rolls muzzle position (inconsequential), muzzle angle (significant), and lateral velocity (significant) into a single data point.
 
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Okay so we can test and find that the node of the barrel is roughly 2.75 inches behind the muzzle.
We also know that adding weight will dampen the amplitude of the barrel which broadens the area under the curve.
So the added weight makes the teeter tottering look flatter.
In our original testing of the welding rod or fishing pole no matter how hard we shook it the standing wave or node never changed its position just it's amplitude.
The flattest we can get the muzzle is by adding weight out in front of the muzzle which moves the node out further.
We can test that by adding length to the welding rod or taping a pencil to the tip of the fishing pole.
Are you still with me?

If yes we can next calculate the weight needed to move the node to the muzzle.
We do that by calculating the weight of the barrel past the node. We know the length is 2.75 inches and let's make the barrel 30 caliber at 1.25 straight cylinder. The weight is then multiplied by 1.5 and we get 1.3 pounds or 20.8 ounces of weight.
We now add 20 ounces to the muzzle 2.75 inches out in front to move the node all the way to the muzzle.
This is as flat as we can make the sine wave or teeter totter.
So your typical 375 cheytac barrel at 1.125 inches needs a tuner around 16-20 ounces and almost 3 inches in front of the muzzle.
This will give the most compensation possible.

Again, I understand everything you're saying.

I'm not necessarily even disputing that there are some harmonic effects occuring.

However, none of the tests that have been shown demonstrate these harmonic effects, nor can you make any conclusions as to the position of the barrel in the Y-axis versus muzzle velocity.
 
Actually you can.
If you add to much weight the groups get larger not smaller.
That happens when the slower bullet leaves later from the muzzle and the barrel is moving downwards not upwards.
The slower and faster shots would never converge at any distance and your groups would suck.
 
Actually you can.
If you add to much weight the groups get larger not smaller.
That happens when the slower bullet leaves later from the muzzle and the barrel is moving downwards not upwards.
The slower and faster shots would never converge at any distance and your groups would suck.

I love data.

If people can show tests that adequately control variables, that are repeatable over multiple tests, I'm all ears.

This kind of data never gets posted.
 
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I understand the theory.

I think it's overly simplistic and unconvinced that it aligns with reality.

But if adequate testing shows otherwise, that's again repeatable, I'm very interested.
 
Actually it is.
If the best your gun will agg is 0.230 inches and you put a tuner on and it now agg's at 0.200 inches how do you explain the 15% decrease in group size?
No changes except the tuner.
 
Actually it is.
If the best your gun will agg is 0.230 inches and you put a tuner on and it now agg's at 0.200 inches how do you explain the 15% decrease in group size?

1. Describe your detailed test procedure.

2. If the results are repeatable over multiple days and conditions, while holding variables constant, then we are getting somewhere.
 
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You take your railgun to the range and shoot 5 targets at 5 shots each. You then add your tuner to the barrel and repeat the test without any changes to your ammunition.
You can do the test until you wear out as many barrels and you feel are necessary. The railgun eliminates the human error.
 

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Facts
1 barrels do move prior to bullet leaving the muzzle .
2. Position of weight on a barrel will change amplitude and rate of movement.
3. Accuracy Nodes do exist.
4. Brass prep when needed does make a difference . Not on brass that is not needed and stacked tolerances adds up.
5 there is no such thang as a generic load that is optimizes on all rifles.
6. Rifles do go out of tune.
7. Tuners do work and can fine tune end results at distance to a level that can not be achieved with just simply load devlopment. (But you must be capable of shooting groups tighter then .600 at 100 yards to experance this if not you will just blame it on natural dispersion) what i find funny is how many shots does it take to know if your rifle shoots like crap do you shoot 100's of shots to find that out?
 
Maybe not quite the same but BPCR shooters, some using smokeless powders, have known this for years using barrel clamps and/or rests.


"There are two good ways to find the nodes on your gun. The first is to ring the barrel with a brass hammer. Go up and down the barrel lightly tapping when you hit a sweet spot you will hear the difference mark the spot and put the center of the Bobsled there. The other is very trick, if you have an octagon barrel lightly coat the top flat with talc. Now go up and down the barrel tapping with a brass hammer. The talc will arrange its self (sic) as the barrel vibrates at a point or two the talc will form little Vs that point at each other. That’s your sweet spot."
 
I have been watching this thread and have watched the video. Haven't shot a pattern yet, not yet sure that I will.

Here is my issue that I can't get past. If you shoot at distance two different loads one a standard load and one a light load and they hit at the same elevation the claim is you have positive compensation because the slow load hit at the same elevation as the faster load.

What if you shoot a standard load and the variable is a hotter load, isn't it going to go really high or is it supposedly on the downward side of the curve and might even shot low?

Maybe if you shoot the 2 charge weights and your standard load is between those two initial charge weights???
 
I have been watching this thread and have watched the video. Haven't shot a pattern yet, not yet sure that I will.

Here is my issue that I can't get past. If you shoot at distance two different loads one a standard load and one a light load and they hit at the same elevation the claim is you have positive compensation because the slow load hit at the same elevation as the faster load.

What if you shoot a standard load and the variable is a hotter load, isn't it going to go really high or is it supposedly on the downward side of the curve and might even shot low?

Maybe if you shoot the 2 charge weights and your standard load is between those two initial charge weights???
See where the two loads are on a graph . That is the only way you will know .
 
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You take your railgun to the range and shoot 5 targets at 5 shots each. You then add your tuner to the barrel and repeat the test without any changes to your ammunition.
You can do the test until you wear out as many barrels and you feel are necessary. The railgun eliminates the human error.

What are your thoughts on the test conducted in post #38? What conclusions can be drawn from that test?
 
I think the idea they are after is seeing how much velocity variation they can compensate for.
i did all that in the early 2000's so now i reload for the best possible groups then I add a properly weighted tuner and look for even smaller groups.
I think Dr Kolbey found he could compensate for around 60 fps on a rimfire round averaging 1054 fps.
Have you used a tuner?
What happened?
 
I think the idea they are after is seeing how much velocity variation they can compensate for.
i did all that in the early 2000's so now i reload for the best possible groups then I add a properly weighted tuner and look for even smaller groups.
I think Dr Kolbey found he could compensate for around 60 fps on a rimfire round averaging 1054 fps.
Have you used a tuner?
What happened?

This is a non-answer.
 
I think you are getting a little bit confused.
Tim and myself have been using tuners for roughly 20 years now.
We are offering up our findings to the general audience.
I gave a very detailed explanation of how to find the correct weight and how far it needs to be out in front of the muzzle and why it needs to be out in front of the muzzle.
This is real world experience not random theory from an unknown internet source.
You keep asking about data and theory.
The grandfather of aeroballist ordnance for nuclear based weapons at Sandia national laboratory explained it all in his book.
Read his book!!!
Dr Geoffrey Kolbe wrote it all up 20 years ago read his articles!
The world's smallest group was shot with a tuner gun look up smallest group ever fired.
These are sources anyone reading this thread can look up and see for themselves.
Yes you can you can disagree with anything but the burden isn't for those seeking to help others to prove to you that your wrong or right.
The Intel is out there and it's up to each individual to use it or not.
I did notice you never answered what tuner you tested or how it turned out.
This needs to be answered so we can help find out why everyone who has actually used a tuner seems to like them and why you disagree that they work.
 
I think you are getting a little bit confused.
Tim and myself have been using tuners for roughly 20 years now.
We are offering up our findings to the general audience.
I gave a very detailed explanation of how to find the correct weight and how far it needs to be out in front of the muzzle and why it needs to be out in front of the muzzle.
This is real world experience not random theory from an unknown internet source.
You keep asking about data and theory.
The grandfather of aeroballist ordnance for nuclear based weapons at Sandia national laboratory explained it all in his book.
Read his book!!!
Dr Geoffrey Kolbe wrote it all up 20 years ago read his articles!
The world's smallest group was shot with a tuner gun look up smallest group ever fired.
These are sources anyone reading this thread can look up and see for themselves.
Yes you can you can disagree with anything but the burden isn't for those seeking to help others to prove to you that your wrong or right.
The Intel is out there and it's up to each individual to use it or not.
I did notice you never answered what tuner you tested or how it turned out.
This needs to be answered so we can help find out why everyone who has actually used a tuner seems to like them and why you disagree that they work.

I'm talking about the specific "test" in post 38. You keep deflecting. I'm not contesting whether tuners "work" or not. I am interested in post #38 - this type of testing seems fairly typical of the average shooter.

What conclusions can adequately be drawn from the test conducted in post #38?
 
If you read post 50 I clearly said let Tim explain it did I not?
Why are you not answering my question?
What tuner are you using and how did it go?

Given all your posts following mine in regards to that specific test, I thought there was interest in discussing it.

I'm interested in discussing the test performed in post #38, and what conclusions we can and can't draw from such a test.
 
I am interested in discussing the tuner you used and your results.
This is a tuner thread so I am positive you must be speaking about your tuner experience

I have two tuners.

I have shot 5x5's with the tuner, without the tuner, and at various tuner settings. No decrease in group size. The best groups were without the tuner (around 1/10 MOA). But not enough testing to draw any dispositive conclusions.

I'm really intersected in post #38. That testing was conducted because of this thread and the information relayed by Tim. So I'm really curious as to what insights and conclusions can be drawn by the test performed in post #38.
 
So you shot 5 groups of 5 shots without a tuner at 0.100 inches then added your tuner and repeated that test and the groups got larger?

Groups were typically larger with the tuner. Best groups were without the tuner, some measuring around 1/10 MOA or less. All groups shot were 5 rounds.

More testing would be required to draw any real meaningful conclusions. My experience with tuners is not dispositive - more testing needs to be done. But for the type of shooting that I do, I don't really see a benefit in my rifle with my reloads.

So to be clear, I'm not saying tuners "work" or don't work. I don't know. That's why I'm interested in tests and data that people show. Like post #38 - I really do want to know what people think in regards to what conclusions can be drawn by that test.
 
Your gun without the tuner putting 25 shots under 0.100 is 0.024 smaller than the current IBS world record at 100 yards so that is one fantastic shooting 6ppc.
I would make very small changes to the tuner your using as most shooters make to big of a change and try it again.
I would also enter that gun into the Supershoot held at kelbleys and see if can get a world title with it.
 
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A Summary

OP - Tuners are neat! Look at this vid!

(discussion follows)

Person #1 - Hey I did a test! Take a look.

Person #2 - Cool! But the test has some flaws. One cannot really draw any conclusions from it.

Person #1 - (silent)

New Person #3 - Why don’t you use your own tuner and do a test? I think the test shows X.

Person #2 - I could do my own test. But from existing tests I want a detailed test procedure and repeatable tests over multiple days with constant variables. Can you help me here?

New Person #3 - Why don’t you use your own tuner and do a test? I think the test shows X.

(repeat last two a bunch)

Person #2 - Sigh.
 
Your gun without the tuner putting 25 shots under 0.100 is 0.024 smaller than the current IBS world record at 100 yards so that is one fantastic shooting 6ppc.
I would make very small changes to the tuner your using as most shooters make to big of a change and try it again.
I would also enter that gun into the Supershoot held at kelbleys and see if can get a world title with it.

It's a 6BRA.

It didn't agg 1/10 MOA, but some groups were that small. Though I think you are purposely trying to be misleading here to somehow disparage me and my credibility. I was pretty clear in not representing that as an agg.

Anyways, I'm interested in discussion around post #38, and the testing that was undertaken due to the original post and topic of the thread.
 
A Summary

OP - Tuners are neat! Look at this vid!

(discussion follows)

Person #1 - Hey I did a test! Take a look.

Person #2 - Cool! But the test has some flaws. One cannot really draw any conclusions from it.

Person #1 - (silent)

New Person #3 - Why don’t you use your own tuner and do a test? I think the test shows X.

Person #2 - I could do my own test. But from existing tests I want a detailed test procedure and repeatable tests over multiple days with constant variables. Can you help me here?

New Person #3 - Why don’t you use your own tuner and do a test? I think the test shows X.

(repeat last two a bunch)

Person #2 - Sigh.
Person 1 has 20 years experience
Person 2 has no experience but his midrange gun outshoots all the 6PPC benchrest rifles in the world.
Person 3 is a national champion with 20 years of tuner experience.
Person 1 is offering free advice to those willing to listen.
Person 2 wants everyone to show him data because he is too lazy to look up the sources offered by Person 3
Person 3 is offering up sources and how to properly fit a tuner for the general masses.
Person 2 just found out Person 3 knows how to look up world records and now Person 2 no longer is shooting good groups.
Person 1 doesn't want to waste his time.
Person 2 has a credibility issue.
Person 3 has gone through all this 20 years ago but has the patience of a saint.
 
It's a 6BRA.

It didn't agg 1/10 MOA, but some groups were that small. Though I think you are purposely trying to be misleading here to somehow disparage me and my credibility. I was pretty clear in not representing that as an agg.

Anyways, I'm interested in discussion around post #38, and the testing that was undertaken due to the original post and topic of the thread.
Everyone who shoots knew it never agg'ed 0.024 under the current world record.
It occasionally shoots a small group.
So you took it to the range and on the same day shooting the same ammo you add some tuner of unknown origin and adjusted it in some unknown fashion and that caused it to shoot larger groups.
Do you have any data showing how a tuner makes a gun shoot larger groups?
Can you give us your theory on why tuners make the groups larger?
And to answer your question about post 38 it looks like the gun needs to be inserted into a return to battery rest to remove the human element from the test
 
I don't know why you keep trying to make this thread about me 🤷‍♂️

A person was inspired by the original post and shot a test, and posted their methodology along with their results.

I think this is really interesting for a number of reasons, and is an interesting discussion. It would be a much more productive conversation in regards to the content of the OP.

And for the record I never concluded that a tuner makes my rifle shoot larger groups. I was very clear in that I can't draw that conclusion from my own testing. That's another misrepresentation of my post(s).
 
So the tuner has 3 options that are possible.
Option 1 your groups shrink
Option 2 your groups don't change
Option 3 your groups get bigger
So now we have ruled out Option 1 and Option 3 correct?
Your groups stayed the same size with the addition of the tuner and you changing its settings?
If your multiple tuners where too heavy the gun would have gone out of tune which it didn't so we can now discount that as the problem.
It appears that your 2 tuners are too light as you aren't seeing any change.
Can you post the weights of those 2 tuners?
 
So the tuner has 3 options that are possible.
Option 1 your groups shrink
Option 2 your groups don't change
Option 3 your groups get bigger
So now we have ruled out Option 1 and Option 3 correct?
Your groups stayed the same size with the addition of the tuner and you changing its settings?
If your multiple tuners where too heavy the gun would have gone out of tune which it didn't so we can now discount that as the problem.
It appears that your 2 tuners are too light as you aren't seeing any change.
Can you post the weights of those 2 tuners?

I haven't ruled out anything with tuners. I fully recognize that my own testing has limitations, of which only limited conclusions can be drawn from.

Which is why I'm really interested in post #38. Someone posted their methodology and results, which was inspired by the OP. I think that would be a really interesting discussion.
 
@kthomas according to what I understand from the video there is not enough velocity change in that test in #38 to make any distinguishable observations
In the test on post 38 his extreme spreads were 28 and 36 fps or close to those numbers.
In my opinion you need an optimal tune first before testing.
I think they were just showing that convergence takes place
 
Let's take this in small steps in the hopes it helps others.
If you have a piece of welding rod or a fishing pole and you shake it up and down it produces a standing wave. Which just means everything looks the same along its length.
A gun barrel does the same thing it's just very small and the human eye doesn't see it. A cantilevered beam if we might.
Now back from the muzzle or back from the front guide or back from the tip of the welding rod we will see a point that looks still called a node.
Are we good so far?


I just don't see how a shot can produce a clearly discernible bending moment and hence transverse wave in a barrel. There are two problems. First, is where does the bending moment come from AND what is the length of that "disturbance relative to the barrel?

If we just take a reasonably good barreled action and clamp it in place so it will not move, then the bullet will exit the barrel, producing both a force backwards and a torque on the barrel. But nothing else. The impulse that produces these forces is of a very long duration compared to the speed of sound in the barrel. Furthermore, the detonation of the powder will create a circular force at the chamber that will travel out. This impulse is very short but still slow compared to the speed of sound. The wave length of deformations from these impulses will be very large compared to the barrel length and will travel many times up and down the barrel before the bullet exits. Thus there will be no sharp single "wave" from the deformation. Stated another way is that the first harmonic of the barrel is many times shorter than the length of the deformation impulse.

I think there is an order of precedence of causes in shot to shot variance and each has to be accounted for. The biggest variable has to be bullet moments of inertia and its interactions with the barrel and its imperfections. Those have to be isolated, measured, and controlled for first.
 
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Person 1 has 20 years experience
Person 2 has no experience but his midrange gun outshoots all the 6PPC benchrest rifles in the world.
Person 3 is a national champion with 20 years of tuner experience.
Person 1 is offering free advice to those willing to listen.
Person 2 wants everyone to show him data because he is too lazy to look up the sources offered by Person 3
Person 3 is offering up sources and how to properly fit a tuner for the general masses.
Person 2 just found out Person 3 knows how to look up world records and now Person 2 no longer is shooting good groups.
Person 1 doesn't want to waste his time.
Person 2 has a credibility issue.
Person 3 has gone through all this 20 years ago but has the patience of a saint.
I am trying to help.

@kthomas , who is not a personal friend, has been very calm and has said multiple, multiple times that he is not saying tuners work or don’t work.

Realize that in order to learn, people ask questions.

Respectfully asked questions are not an attack.

If people don’t want to talk about their test, so be it. Perhaps help the questioner with what he is looking for.

“Look in the book” is…maybe…not…the most helpful answer.

Maybe the data he is looking for will not tell him what he thinks it will. Perhaps think of a nice way to tell him that and include some elucidation. Perhaps pretend he is in his first year of stats and assume an air of grandfatherly kindness.

In the test on post 38 his extreme spreads were 28 and 36 fps or close to those numbers.
In my opinion you need an optimal tune first before testing.
I think they were just showing that convergence takes place
I think you are now maybe on the right communication path.

In case it is not obvious, I am not attacking you, nor anyone else. I was making light of the situation as it unfolded, as my eyes saw it.
 
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I just don't see how a shot can produce a clearly discernible bending moment and hence transverse wave in a barrel. There are two problems. First, is where does the bending moment come from AND what is the length of that "disturbance relative to the barrel?

If we just take a reasonably good barreled action and clamp it in place so it will not move, then the bullet will exit the barrel, producing both a force backwards and a torque on the barrel. But nothing else. The impulse that produces these forces is of a very long duration compared to the speed of sound in the barrel. Furthermore, the detonation of the powder will create a circular force at the chamber that will travel out. This impulse is very short but still slow compared to the speed of sound. The wave length of deformations from these impulses will be very large compared to the barrel length and will travel many times up and down the barrel before the bullet exits. Thus there will be no sharp single "wave" from the deformation. Stated another way is that the first harmonic of the barrel is many times shorter than the length of the deformation impulse.

I think there is an order of precedence of causes in shot to shot variance and each has to be accounted for. The biggest variable has to be bullet moments of inertia and its interactions with the barrel and its imperfections. Those have to be isolated, measured, and controlled for first.
All shots bend out of all firearms it's called trajectory.
Your explanation would be do all groups fired with the same powder charge produce the same size group?
In ELR if we loaded 5 shots each at 90 92 94 96 and 98 grains would they all shoot the same size groups with just a small variation in point of impact?
The answer is no one weight would consistently shoot better than all the others.
 
I am trying to help.

@kthomas , who is not a personal friend, has been very calm and has said multiple, multiple times that he is not saying tuners work or don’t work.

Realize that in order to learn, people ask questions.

Respectfully asked questions are not an attack.

If people don’t want to talk about their test, so be it. Perhaps help the questioner with what he is looking for.

“Look in the book” is…maybe…not…the most helpful answer.

Maybe the data he is looking for will not tell him what he thinks it will. Perhaps think of a nice way to tell him that and include some elucidation. Perhaps pretend he is in his first year of stats and assume an air of grandfatherly kindness.


I think you are now maybe on the right communication path.

In case it is not obvious, I am not attacking you, nor anyone else. I was making light of the situation as it unfolded, as my eyes saw it.
Nobody here is forced to give answers to any questions posted.
If your seeking advice it is often times useful to listen.
Yes ask all the questions you need but make sure an ask a useful question.
Show me data isn't a good question when there is 35 plus years on this subject and a U.S. Patent that explains it all.
If someone says turbochargers produce more power I would do a Google search to see if they do or don't.
I wouldn't ask bore warner to show me data on an engine building forum and argue for 2 pages that millions of engines and dyno results are wrong.
I am actually at the gun range as I type this and think kthomas has a gun shooting well enough that he should see real world results if he uses the right tuner.
I am guessing since he mentions 6 BRA he is running heavy bullets through a number 17 contour barrel 28-30 inches long and needs a 8-12 ounce tuner.
 
Nobody here is forced to give answers to any questions posted.
If your seeking advice it is often times useful to listen.
Yes ask all the questions you need but make sure an ask a useful question.
Show me data isn't a good question when there is 35 plus years on this subject and a U.S. Patent that explains it all.
If someone says turbochargers produce more power I would do a Google search to see if they do or don't.
I wouldn't ask bore warner to show me data on an engine building forum and argue for 2 pages that millions of engines and dyno results are wrong.
I am actually at the gun range as I type this and think kthomas has a gun shooting well enough that he should see real world results if he uses the right tuner.
I am guessing since he mentions 6 BRA he is running heavy bullets through a number 17 contour barrel 28-30 inches long and needs a 8-12 ounce tuner.

It's easy to measure the output that a turbocharger creates. It's relatively easy to perform a test in which variables are controlled, and the resulting output can be conclusively linked to the variable being tested (turbocharger, in this specific example).

In the world of internal and external ballistics, it is much more difficult to independently control and measure variables and their respective inputs on ballistic performance.

A patent isn't data. A hypothesis or idea isn't data.

For the record, I'm not saying whether tuners "work" or don't work. I truly don't know - and every tuner advocate has a different answer for what a tuner can actually do. I'll admit that I'm skeptical, however I'm very intrigued by the topic. I like seeing real world results with tuners, but I've yet to see a test and its corresponding results posted in which we can adequately draw conclusions from. This doesn't mean that tuners don't work. I truly don't know. But so far from what I've seen, people have a tendency to draw very strong conclusions from very weak datasets and testing procedures.

For example, I think the idea behind the test performed in post #38 is pretty interesting. But I don't see how any conclusions can be drawn from it. There are 4 shots in a row of the exact same MV, but with different results. Is that because the rifle and ammo just isn't precise enough to put every bullet in the same hole with the same MV? Is it a shooter related issue? Or are the results being influenced by other variables that aren't necessarily being controlled or accounted for - such as consistency in the ignition system, or a variable with the ammo that influences internal ballistics? Or countless other things? There are so many factors that contribute to internal ballistics that we can only control to such a degree of precision - and this is never accounted for in tests regarding tuners.

I would love to see more tests like in post #38 and see what they look like. Can you actually map the position of the bore with a corresponding MV? Is the test reliable and repeatable? What are the limitations of such testing, and what conclusions can we realistically draw?
 
I gave you a test example early on but for some reason you don't want to try it for yourself.
Anyone that has used a tuner knows within 3 minutes if the tuner has any influence on how the gun shoots this is why I have a tendency to think some people have never used a tuner or where spinning it wildly without paying alot of attention to what was happening.
If I move my tuner 1/32 of an inch I see results. I mean 1/32 on the outer weight not the length from the muzzle.
 
In the test on post 38 his extreme spreads were 28 and 36 fps or close to those numbers.
In my opinion you need an optimal tune first before testing.
I think they were just showing that convergence takes place
Ya he had ES that may be in the realm of showing a difference between 2 shots but not enough to see any sort of trend or pattern.
 
I gave you a test example early on but for some reason you don't want to try it for yourself.
Anyone that has used a tuner knows within 3 minutes if the tuner has any influence on how the gun shoots this is why I have a tendency to think some people have never used a tuner or where spinning it wildly without paying alot of attention to what was happening.
If I move my tuner 1/32 of an inch I see results. I mean 1/32 on the outer weight not the length from the muzzle.

I'm sorry I didn't shoot your test right away. I wish that my life allowed for the opportunity to only focus on shooting and going to the range at the drop of a hat.

When I get around to it, I will play with tuners again. I don't have a rail gun like you, so there will be limitations.

I don't think it's fair to say that 3 minutes is all it takes. I've shot numerous groups with different tuner settings, and the test was far from conclusive. Saying it only takes 3 minutes with a tuner to draw conclusions really discounts the complexity of internal and external ballistics, and minimizes the reality of variables that are out of our control or can only be controlled to a certain degree of precision.

I would love to see more people shoot a test like in post #38, ideally multiple ladders so you can start to get a true sense what relationship (if any) between MV and bore amplitude exists. Multiple tests that show repeatable results would be interesting.
 
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If anyone posting here or reading this has a tuner on there rifle and doesn't see it affecting the groups in 3 minutes at the range there is not only a problem but a huge problem.
To anyone viewing this thread move your tuners weight only a fraction of an inch on the order of 1/64th to 1/32 of an inch.
You can put a stripe on the tuner as a witness mark.
I will post some pictures when I am done shooting that show the movement.