Rimfire Tuners

[gunsandgunsmithing]

One thing your last drawing oversimplifies is amplitude, with and without a tuner. Physics will tell us that amplitude is reduced by adding a mass to the end of the barrel. Interestingly, for the very short period while the bullet is still in the barrel, this was not the case in my testing. Initial amplitude was actually INCREASED but it quickly dissipates to a lower amplitude than without a tuner.
If you think about it, it makes sense because the barrel is already deflecting downward more with the weight, than without it, even before the trigger is pulled. This is why a typical, even undamped tuner will widen the node beyond simply lowering the frequency of vibration. I found this an interesting point from testing. In simple terms, the barrel spends more time at top and bottom.

 

[1Merlin]

Stowaway.. Sir. Are you Klaus Dieter Roth the German National ISSF Coach?

 

[Bginvestor]

One thing your last drawing oversimplifies is amplitude, with and without a tuner. Physics will tell us that amplitude is reduced by adding a mass to the end of the barrel. Interestingly, for the very short period while the bullet is still in the barrel, this was not the case in my testing. Initial amplitude was actually INCREASED but it quickly dissipates to a lower amplitude than without a tuner.
If you think about it, it makes sense because the barrel is already deflecting downward more with the weight, than without it, even before the trigger is pulled. This is why a typical, even undamped tuner will widen the node beyond simply lowering the frequency of vibration. I found this an interesting point from testing. In simple terms, the barrel spends more time at top and bottom.

Is your point that the added inertia from the mass of the tuner shapes the barrel's harmonic peaks such that its flatter so if u can get a bullet to release from muzzle at the peaks, shot to shot variability will group the tightest??

 

[CharlieNC]

Hello 1Merlin,
Yes a little. Sometimes I give ISSF Shooter support.

View attachment 1222095

And now a little technical info and that's good.
In Germany, the benchrest scene is little.
View attachment 1222096

Another example with a standard M54 barrel with slow and fast ammunition.
View attachment 1222097

That's all. Many Greetings.

This is a little confusing to me in that the other studies I have seen show improved accuracy prior to the amplitude max, such that faster bullets exit at a lower angle which "compensates" for the reduced drop due to velocity. Of course the max would be favorable if there is no velocity variability. Can you elaborate more as you clearly have considerable experience?

 

[gunsandgunsmithing]

Is your point that the added inertia from the mass of the tuner shapes the barrel's harmonic peaks such that its flatter so if u can get a bullet to release from muzzle at the peaks, shot to shot variability will group the tightest??

I can see how you'd come to that conclusion but with more amplitude, the arc is simply larger. And in principle, amplitude and frequency are totally separate from one another. So, a bigger arc at a given frequency equals more "dwell" time at top and bottom., for lack of a better word.

 

[grauhanen]

Stowaway.. Sir. Are you Klaus Dieter Roth the German National ISSF Coach?

Looking at the length of the name that was covered in the images of the postcards, the name seems longer than four letters.

 

[The stowaway]

Thanks for looking
I am not Klaus Dieter Roth.
(American shooters seek out and chase Mr. No )

 

[Hi-NV Shooter]

Hi, only for information.
everyone has his method, most shooters test with trial and error.
Benchrest shooters can use a tuner. In some disciplines no tuner is allowed.
There you have to search for harmony using the speed of the bullet,
or to change the vibration with a weight at the mouth.

At the turning point, the pendulum speed is zero.
View attachment 1222024

for the bullet this is the best moment to leave the muzzle
View attachment 1222025

To measure the best moment, I built a measuring device.
(it was not easy, my hair turned gray )
View attachment 1222030

So I can just check the harmony or the right moment.
View attachment 1222031

Thanks for the attention.
Greetings.

Hi Stowaway,
Below I have quoted your statement:
At the turning point, the pendulum speed is zero. for the bullet this is the best moment to leave the muzzle.
correct me if I am wrong, but it seems your testing has verified in a sense what Bill Calfee has been saying for years about a stopped muzzle. also your animation of the barrel's movement also seems to be indicating the best exit point for the bullet is at the top or just prior to peak.
again if I am wrong, please explain.

Lee

 

[gunsandgunsmithing]

Hello 1Merlin,
Yes a little. Sometimes I give ISSF Shooter support.

View attachment 1222095

And now a little technical info and that's good.
In Germany, the benchrest scene is little.
View attachment 1222096

Another example with a standard M54 barrel with slow and fast ammunition.
View attachment 1222097

That's all. Many Greetings.

Back to the subject, frequency is just a term that describes the number of cycles in a second. Given a repeating waveform, there will be a repeating of when the barrel is at the top of it's oscillation, providing repeating "sweet spots" at same or very similar intervals. IOW, multiple sweet spots, not one magical tuner setting for all speeds of ammo.

 

[The stowaway]

Hmm?
What should I write now?
I read about barrel vibrations: Carl Cranz (1858 - 1945) Professor at the Technical University of Berlin. About Bill Calfee ... to Geoffrey Kolbe. And a lot more. (But that is not important).

I made my first experiments with barrel vibrations with dial gauges. Two dial gauges broke during the tests. Then I stopped. My finding dial gauges are not useful. The vibrations are too hard and too fast. The measuring pressure on the barrel is much too high and affects the vibration.

After reading G.J. Wasser and Geoffrey Kolbe it was clear to me that a non-contact measurement on the Muzzle brings the best results. Neither of them talk about nodal points. For me the vibration on the Muzzle is important. And nothing else. And I have not yet seen a mouth that does not vibrate or vibrates little. Unfortunately.

Sorry I forgot. For bullet tests (To test the precision of the bullets) I've already experimented with a fixed muzzle.


Number 4.) doesn't really exist for me.



Conclusion
You can think or test what you want.
Greetings

 

[Hi-NV Shooter]

Hmm?
What should I write now?
I read about barrel vibrations: Carl Cranz (1858 - 1945) Professor at the Technical University of Berlin. About Bill Calfee ... to Geoffrey Kolbe. And a lot more. (But that is not important).

I made my first experiments with barrel vibrations with dial gauges. Two dial gauges broke during the tests. Then I stopped. My finding dial gauges are not useful. The vibrations are too hard and too fast. The measuring pressure on the barrel is much too high and affects the vibration.

After reading G.J. Wasser and Geoffrey Kolbe it was clear to me that a non-contact measurement on the Muzzle brings the best results. Neither of them talk about nodal points. For me the vibration on the Muzzle is important. And nothing else. And I have not yet seen a mouth that does not vibrate or vibrates little. Unfortunately.

Sorry I forgot. For bullet tests (To test the precision of the bullets) I've already experimented with a fixed muzzle.

View attachment 1222763
Number 4.) doesn't really exist for me.

View attachment 1222764

Conclusion
You can think or test what you want.
Greetings

Very interesting how you state #4 really doesn't exist for ME? like you are leaving the door open to see if it can for someone else?
there are a lot of graphs being displayed in this thread, but no actual targets of what the graphs are showing.
I don't know if the stopped muzzle really exist, I do know there can be multiple settings that can shoot really well, but ONLY one setting will shoot day in and day out, using the best lots available that have been tested for that rifle. if you have to adjust the tuner for every different lot you test or use or for every weather change, it simply is not the setting for that complete shooting setup/package. you are simply shooting one of the multiple settings that shoot only really well.
how can I say this, ask any of the top 5 RFBR shooters who have won at the highest levels consistently and I am pretty sure all will say once they found a setting for the tuner , they have not touched it since. and just simply test for the best ammo lots they can find!

Lee

 

[linekin]

how can I say this, ask any of the top 5 RFBR shooters who have won at the highest levels consistently and I am pretty sure all will say once they found a setting for the tuner , they have not touched it since. and just simply test for the best ammo lots they can find!

Lee

Lee, I've been to several IR50 Nationals & on Friday/ test day & most at the top of they're game adjusted their tuner. Calfee guys included. They most likely don't touch them after that.
Was it due to location, indoors/outdoors, new barrel, rest, ammo, etc I don't know. But most get moved. I too was surprised by that.

Keith

 

[Hi-NV Shooter]

Lee, I've been to several IR50 Nationals & on Friday/ test day & most at the top of they're game adjusted their tuner. Calfee guys included. They most likely don't touch them after that.
Was it due to location, indoors/outdoors, new barrel, rest, ammo, etc I don't know. But most get moved. I too was surprised by that.

Keith

Hey Keith Happy New Year!, Thanks for chiming in. that is very interesting and surprising to hear, but are these the same shooters that are considered the top 5, I am pretty sure TKH had said in a reply to me here, he doesn't touch the tuner once he sets it. this is the caliber of shooters I am talking about. I use them as an example as these are the ones everyone are chasing and setting the bar for everyone to reach for.

Lee

 

[linekin]

Hey Keith Happy New Year!, Thanks for chiming in. that is very interesting and surprising to hear, but are these the same shooters that are considered the top 5, I am pretty sure TKH had said in a reply to me here, he doesn't touch the tuner once he sets it. this is the caliber of shooters I am talking about. I use them as an example as these are the ones everyone are chasing and setting the bar for everyone to reach for.

Lee

Yes the same caliber shooters Lee. I'm pretty certain they weren't polishing fingerprints off.lol
As I said maybe they had new equipment, or it was just a different venue. I don't know.
I think you know I freely move mine. Likely I'm chasing a less than perfect tune. I think there's only been a couple/three lots I've had where I didn't have to make slight adjustments throughout the season for whatever reason. Its all ammo dependent as you know.
Wishing you a Happy & Prosperous New Year as well!,
Keith

 

[Hi-NV Shooter]

Yes the same caliber shooters Lee. I'm pretty certain they weren't polishing fingerprints off.lol
As I said maybe they had new equipment, or it was just a different venue. I don't know.
I think you know I freely move mine. Likely I'm chasing a less than perfect tune. I think there's only been a couple/three lots I've had where I didn't have to make slight adjustments throughout the season for whatever reason. Its all ammo dependent as you know.
Wishing you a Happy & Prosperous New Year as well!,
Keith

Keith, Thank you for the clarification on the shooters you seen adjusting tuners. coming from you I have no doubt they weren't wiping off fingerprints lol
perhaps I am wrong about what has been said all these years, I do know from my own experience once I find a tune I don't have to touch it.

Lee

 

[BP1]

BP1,
To answer your original question, I am currently using Stiller tuners. They are similar to the Harrell's, but with tighter tolerances and additional locking screws. Several guys I know are now using Stiller tuners and are very happy with them, myself included. I have had an Ezell years ago (sold it), several Harrell's (two still in use), Pro-X (in use), and my second Stiller is coming soon. Future tuner purchases will be Stiller.

I have no idea why the Pro-X has different threads on the optional brass weight. I do know the brass weight is made available to bring the weight of the tuner up to what a Harrell weighs since the Pro-X is lighter than the Harrell. I can only 'guess' that if one wanted to add weight that the MFG thought the first step for the end user would be to go to the Harrell weight first? Don't know for sure.

As you have figured out, Riverside/Harrell's weights fit the fine threaded end of the brass weight. The Pro-X can be ordered with, or without the brass weight. Without the brass weight typical weights can not be used.

There has been hundreds of pages written on forums discussing tuners and tuning. Pretty much everything under the sun has been discussed and the opinions and methods range from one extreme to the other. Since I had a few different tuners and you were asking about what people use, I threw one in no one has mentioned, and several people I know like them very much. Your Pro-X is up to the task with the proper amount of testing. I won't be selling mine, but as mentioned, my future tuner purchases will be Stiller. Good luck with your tuning.
Scott

Scott,are the stiller tuners setup like the Harrells to where it will except bloop tube?

 

[VLNBYR]

Scott,are the stiller tuners setup like the Harrells to where it will except bloop tube?

If Stiller makes it it is first class and done right. Yes they are threaded to accept weights and tubes. Sorry Scott.

 

[holstil]

Appears to me that screwing the tuner in or out to find the lowest point of impact may be beneficial (as mentioned positive compensation)? If so, is this the equal to or related to seating depth in center fire? The benefit of center fire over rim fire being we can lengthen dwell period with charge weight? Would this then be the equal to testing different lots of ammo? This has been my focus when testing now. Could this be why when I've found a sweet spot for seating depth, the powder charge matters less?
What little experience I had with frequency analysis escapes me. Reminds me of playing with an oscilloscope, I need to get my thinking in gear.
Gunsandgunsmithing, thanks for the recap. It's either coming together or falling apart here for me. Lol

 

[gunsandgunsmithing]

Appears to me that screwing the tuner in or out to find the lowest point of impact may be beneficial (as mentioned positive compensation)? If so, is this the equal to or related to seating depth in center fire? The benefit of center fire over rim fire being we can lengthen dwell period with charge weight? Would this then be the equal to testing different lots of ammo? This has been my focus when testing now. Could this be why when I've found a sweet spot for seating depth, the powder charge matters less?
What little experience I had with frequency analysis escapes me. Reminds me of playing with an oscilloscope, I need to get my thinking in gear.
Gunsandgunsmithing, thanks for the recap. It's either coming together or falling apart here for me. Lol

I tune for bullet exit at/near top of bbl swing.

 

[holstil]

Ok, I assume you have many tests as to why. I’ll look in that direction more.