Tuners Spinning Out Of Control

Vibe, I have allready proven with these rt barrels velocity differences can be tuned in excess of 60fps, are you saying 80, 100, 150 are possible? right now I can't find ammo with the same lube to test exactly the difference. martin
 
Vibe, where are you going to find ammo to test beyond the 60 fps variance these rt with a 4.5-4.7 oz can tune?
 
The Science:

What I find most frustrating about the introduction of "Science" into these conversations is the science seems only ever used to prove some non-scientist, who is experimenting, to be wrong. The science never seems to be applied in any useful way that hastens the "Fix" of the problem being worked on. What good is the science if it never takes us "Home"?

It would seem to me with all the brilliant minds contribuiting here, armed with all the formulas and scinece could, fairly easily, make rifles shoot a wide variety of ammunition. They wouldn't have to actuly do any of the machining or mechanical side of the effort but simply work out the problem scientifically to a conclusion. It is my longing for a CONCLUCION that leads me to write this. Certainly there must be at least one scientist who is interesteded in something more than rebutting others. Take us home, PLEASE! I'm thinking there is a lot of money that can be made by doing so.
 
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Pete Wass said:
What I find most frustrating about the introduction of "Science" into these conversations is the science seems only ever used to prove some non-scientist, who is experimenting, to be wrong. The science never seems to be applied in any useful way that hastens the "Fix" of the problem being worked on. What good is the science if it never takes us "Home"?

It would seem to me with all the brilliant minds contribuiting here, armed with all the formulas and scinece could, fairly easily, make rifles shoot a wide variety of ammunition. They wouldn't have to actuly do any of the machining or mechanical side of the effort but simply work out the problem scientifically to a conclusion. It is my longing for a CONCLUCION that leads me to write this. Certainly there must be at least one scientist who is interesteded in something more than rebutting others. Take us home, PLEASE! I'm thinking there is a lot of money that can be made by doing so.
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damn!! you have put the only post that counts up on this subject!!!! thank you. please share anymore pearls of wisdom with us that everybody can understand!! lord knows the scientists on here aren't telling us anything we can use yet. maybe they will get around to it sooner or later. hopefully more sooner than much later.
 
Pete Wass said:
What I find most frustrating about the introduction of "Science" into these conversations is the science seems only ever used to prove some non-scientist, who is experimenting, to be wrong. The science never seems to be applied in any useful way that hastens the "Fix" of the problem being worked on. What good is the science if it never takes us "Home"?

It would seem to me with all the brilliant minds contribuiting here, armed with all the formulas and scinece could, fairly easily, make rifles shoot a wide variety of ammunition. They wouldn't have to actuly do any of the machining or mechanical side of the effort but simply work out the problem scientifically to a conclusion. It is my longing for a CONCLUCION that leads me to write this. Certainly there must be at least one scientist who is interesteded in something more than rebutting others. Take us home, PLEASE! I'm thinking there is a lot of money that can be made by doing so.
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That's one of the real problems here, and I agree with this post completely. This has been one big stumbling block - many of the people actually doing the "machining and mechanical", so to speak, are the very ones ignoring the science - or making up their own version of physical laws and mechanics of materials. So it's real hard to get any data from them..much less any good workable data. I agree with you Pete, one would think that taking this problem closer to a conclusion would be seen as one of the biggest "advancements of rimfire accuracy"...apparently there are many that would rather do it their way instead.
I've never posted with the intention to prove anyones results were wrong..just that the theories behind the successes seemed to be flawed.
 
Perhaps I could become a "Match Maker"?

Vibe said:
That's one of the real problems here, and I agree with this post completely. This has been one big stumbling block - many of the people actually doing the "machining and mechanical", so to speak, are the very ones ignoring the science - or making up their own version of physical laws and mechanics of materials. So it's real hard to get any data from them..much less any good workable data. I agree with you Pete, one would think that taking this problem closer to a conclusion would be seen as one of the biggest "advancements of rimfire accuracy"...apparently there are many that would rather do it their way instead.
I've never posted with the intention to prove anyones results were wrong..just that the theories behind the successes seemed to be flawed.
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It seems simple enough to me to meld the science with the machining and mechanical. All there needs to be is Communication and the desire for both parties to do something monumental. What appears to happen is egos get in the way of everything, including good science.

The truth in this appers to be there are thinkers and there are dooers. In my opinion, most of the dooers either have not had the oportunity to acquire a Scientific Education or are not interested in that segment of Education. Most people think but thinking alone does not solve problems. Actually making things to try to affect a change is usually wins out.

It surves no purpose for folks who know the science to try to goad others in acquiring the same level of education they have nor does it serve any purpose to continuously be sticking their finger in the Dooer's eye. The Scientific folks would be a lot better off to partner up with a dooer and become part of the team; get something done or make the conclusion happen. There is no shame or sin in being ignorant. One must realize that it takes all kinds of interests to make up humanity. We need to work together indstead of seperately.
 
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Pete Wass said:
It seems simple enough to me to meld the science with the machining and mechanical. All there needs to be is Communication and the desire for both parties to do something monumental. What appears to happen is egos get in the way of everything, including good science.

The truth in this appers to be there are thinkers and there are dooers. In my opinion, most of the dooers either have not had the oportunity to acquire a Scientific Education or are not interested in that segment of Education. Most people think but thinking alone does not solve problems. Actually making things to try to affect a change is usually wins out.

It surves no purpose for folks who know the science to try to goad others in acquiring the same level of education they have nor does it serve any purpose to continuously be sticking their finger in the Dooer's eye. The Scientific folks would be a lot better off to partner up with a dooer and become part of the team; get something done or make the conclusion happen. There is no shame or sin in being ignorant. One must realize that it takes all kinds of interests to make up humanity. We need to work together indstead of seperately.
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Pete,
Well stated. You can't convince anyone if they aren't ready.

Joe
 
Pete Wass said:
It seems simple enough to me to meld the science with the machining and mechanical. All there needs to be is Communication and the desire for both parties to do something monumental. What appears to happen is egos get in the way of everything, including good science.
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True, but in some case that's all it is. Just the appearance of egos getting in the way. But it seems there is a distinct lack of listening skills involved. Give me some hard evidence that my views are incorrect and I will definitely entertain the notion that I am not an expert. Oh heck I'll state up front that I'm not an expert, but though I might not be able to solve the entire problem - I can recognize things that run counter to what I have learned. I'm willing to learn more and change my point of view, but the derivation of that change will have to follow a logical progression. A simple statement of "that is wrong" without any reasoning to back it up will not do. And I do not, and as far as I know, have not expected that from anyone else. I have attempted to back up my objections with reason why I objected that were based upon what I know to be true of sound physical principles.

Pete Wass said:
The truth in this appears to be there are thinkers and there are doers. In my opinion, most of the doers either have not had the opportunity to acquire a Scientific Education or are not interested in that segment of Education. Most people think but thinking alone does not solve problems. Actually making things to try to affect a change is usually wins out.
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What Bill Calfee has accomplished is a prime example of this, but he's only part way to "solving" the issue...I find it extremely frustrating to see him getting so close only to build roadblocks for himself, impeding further progress because of his incorrect grasp of the physics involved. I'd love it if he could find a way to really communicate what he knows to Varmint Al, and vice versa. Of course he would have to let go (or at least modify) this perception of a parallel node that does not exist or behave in the manner he is so enamored of.

Pete Wass said:
It serves no purpose for folks who know the science to try to goad others in acquiring the same level of education they have nor does it serve any purpose to continuously be sticking their finger in the Doer's eye. The Scientific folks would be a lot better off to partner up with a doer and become part of the team; get something done or make the conclusion happen. There is no shame or sin in being ignorant. One must realize that it takes all kinds of interests to make up humanity. We need to work together instead of separately.
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If you figure out a way to get that to happen...Let me know. I'll help in what ever limited way I can.
 
Vibe said:
... someone built a high rpm gyro and mounted it to the muzzle of a rifle ... produced some fairly respectable increases in offhand accuracy.
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Now that is an original idea! Comparing offhand accuracy leaves some questions about whether it would benefit BR rifles, but still very interesting. One of the not-so-useful properties of a gyro is that torque around one axis causes motion around a perpendicular axis. So vibration in the vertical plane would actually cause shot dispersion in the horizontal plane.

Vibe said:
...what we want ... is enough mass at he muzzle to cause the First order oscillation to be near motionless at the top of it's swing at bullet exit, while at the same time causing the 2nd order vibration (the one with a node at the muzzle) to track the range of vertical that points the slow shots high and the fast shots lower in such a way that they hit the same point at the target.
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Al points out that the bullet exit time is so short that harmonic vibration doesn't have time to be established. It is a transient forced motion problem. The first and second modes have frequencies of about 80 and 400 Hz, respectively, so they are too slow to have become steady vibrations in the few milliseconds that it takes the bullet to leave the barrel. If anything, the barrel shape at bullet exit (http://www.varmintal.com/amode.htm) looks more like the third mode (1 KHz), with a node at mid barrel and another closer to the muzzle.

Further, I suspect that the barrel being at the top of its swing is fundamentally incompatible with the muzzle angle rising. Al's simulations and ours seem to indicate that muzzle angular velocity lags roughly 90 degrees of phase behind muzzle height. When the muzzle is at the top of its swing, its angular speed is low and not useful for tuning. But as the muzzle accelerates downward, the muzzle angle rises quickly. The best point for tuning heavy barrels would tend to be when the muzzle angle is rising the fastest, which ironically, may coincide with the fastest downward muzzle velocity near the middle of its up/down travel.

Happy Holidays,
Keith
 
I am not here to get into any pis**g contest or blow my own horn.
Will a barrel that has some degree of stress relief as those buttoned verses a cut rifle barrel have the same tuning ability? The reason i ask is that with the cut barrels that i am getting now the tuning range is a lot broader. A Harrels tuner set at 200 will tell if the .875 barrel will be competetive. This is with a 4 groove, 5 groove and a Metford.
 
GordonE said:
I am not here to get into any pis**g contest or blow my own horn.
Will a barrel that has some degree of stress relief as those buttoned verses a cut rifle barrel have the same tuning ability? The reason i ask is that with the cut barrels that i am getting now the tuning range is a lot broader. A Harrels tuner set at 200 will tell if the .875 barrel will be competetive. This is with a 4 groove, 5 groove and a Metford.
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Gordon,
At the moment my best barrel is a Border and I’m seeing a larger tuning range too, I thought it was just this barrel but maybe it is something to do with cut riffling.

Peter
 
GordonE said:
I am not here to get into any pis**g contest or blow my own horn.
Will a barrel that has some degree of stress relief as those buttoned verses a cut rifle barrel have the same tuning ability? The reason i ask is that with the cut barrels that i am getting now the tuning range is a lot broader. A Harrels tuner set at 200 will tell if the .875 barrel will be competetive. This is with a 4 groove, 5 groove and a Metford.
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Mr Eck -without giving up any trade secrets would you mind specking out the ultimate rimfire barrel to your specs. You have already mentioned .875 diameter, maybe what length and do you have a specific length you like. Tuner weight you like and maybe bullet speed. Does the length have to be exact or is their a plus or minus spec. thank you joe
 
Gordon, how many clicks either way of 200 does the .875 maintain the tune, also have you noticed any lessening in the need for fouling shots.
 
mks said:
Further, I suspect that the barrel being at the top of its swing is fundamentally incompatible with the muzzle angle rising. Al's simulations and ours seem to indicate that muzzle angular velocity lags roughly 90 degrees of phase behind muzzle height. When the muzzle is at the top of its swing, its angular speed is low and not useful for tuning. But as the muzzle accelerates downward, the muzzle angle rises quickly. The best point for tuning heavy barrels would tend to be when the muzzle angle is rising the fastest, which ironically, may coincide with the fastest downward muzzle velocity near the middle of its up/down travel.

Happy Holidays,
Keith
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See. There is where the specific moment of inertia of the tuner comes into play. At the top of the 1st order swing the muzzle is at the 1st order anti node - with the correct tuner mass this is also when the bullet exits. However this point is also the first 2nd order node - where angular velocity is at it's highest - and with a tuner with the correct Moment of Inertia this angular motion compensates for relatively small variations in muzzle velocity. Also I think I'm seeing that the sudden increase in barrel diameter of some of the reverse taper barrels might even mimic a condition, which could be mistaken for a "parallel node" - in that it is structurally removed from the propagated stress waveform - and results in a short straight bore section at the muzzle.

At the instant of the bullet leaving under these conditions there would be no yaw imparted to the bullet by a barrels transverse motion. the muzzle would be an instantaneous pivot point, being essentially stationary in the 1st order motion as well as the 2nd order, the short straight section would allow bullet stability to form while still in the choked area, and the escaping muzzle gasses would pass almost uniformly around all tangents to the bullet. Elimination of all of these sources of initial bullet yaw would have to help maintain a stable trajectory down range.
 
I deleted that, not my thread. I would appreciate Gordons response to number of clicks before any tune change and if he noticed a change in number of fouling shots.
 
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Gordon,
Now I see what you're getting at. I don't read this forum everyday and sometimes get lost in long threads but I looked for your response (more than once) and found what you want. I have never owned a cut rifled barrel but I don't think tune would be affected by either (assuming same diameter and length so it's apples to apples). Accuracy wouldn't either. Of course I'm assuming the folks building them do their part. I believe barrel length has more to do with tune (with a tuner of course) rather than any other aspect of the barrel. That's my thoughts.

John M. Carper
 
GordonE said:
I am not here to get into any pis**g contest or blow my own horn.
Will a barrel that has some degree of stress relief as those buttoned verses a cut rifle barrel have the same tuning ability? The reason i ask is that with the cut barrels that i am getting now the tuning range is a lot broader. A Harrels tuner set at 200 will tell if the .875 barrel will be competetive. This is with a 4 groove, 5 groove and a Metford.
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My 2 cents from a materials standpoint is that the residual compressive stresses from button rifling will cause a barrel to behave differently than a barrel with cut rifling. I suspect that the button rifled barrel will want to stay "straighter" in general than a cut rifled barrel (like a pre-stressed beam). I also suspect that a cut rifled barrel will want to behave in a more natural, relaxed manner than a button rifled barrel. This is just postulation, but we can definitely expect differences in material behavior depending on residual stresses.

SteveM.
 
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