Help Me Design a Tuner Test

[dgeesaman]

Maybe this has been mentioned but I suggest using a matched lot for the gun, matched by testing without a tuner or the tuner at an arbitrary baseline setting.
Two reasons: 1) you could have a hard time discerning the tune if the groups are generally poor 2) you can justify telling customers to leave off their tuner for tunnel testing unless they are very confident in the tune.

Then if you're successful, I suggest taking the *worst* ammo lot for the gun (not cheap stuff, just good match ammo that it didn't like) and see if you can 'tune' that ammo to shoot well. Most of us will expect it won't work, but having data to show it is much better. But there are some who assume they can use their tuner to make any lot of good quality ammo shoot well.

BTW congrats on SB Nationals. I was getting reports from our clubs shooter in attendance and the 3rd hand info said "some Palma guy" was running the table and managing the electronic targets and wind reading differently/better than the rest. I laughed when I looked it up and saw it was you. I told them you're not just "some" Palma guy.

 

[Straightshooter1]

Yep! I get the pc aspect but otherwise, I don't see any difference rf vs cf in this regard. PC is there with or without a tuner and with both rf and cf. I truly feel people make this much harder than it is, mostly by randomly moving the tuner in some large increment, without a known reason for whatever increment they use. Doesn't matter what tuner...ya gotta establish increment values. Without knowing what to expect, you're simply moving and hoping. That's not what I'd call a methodical approach but hey, if it works for you, don't change a thing.

The test target above, albeit cf, shows top and bottom of bbl swing, how many marks from top to bottom as well as how many between extreme in to out of tune and group shapes that I look for. Those shapes are predictable and repeatable! That's the basis for how I use a tuner. Without that predictability, it would not work. It's not only about the smallest group on the test either, as one thing confirms the other making it very statistically significant without firing thousands of rounds and such as that. For example, tuner setting 0 looks good but I would not use that setting as the next couple of groups do not display what I look for nor is it at top or bottom of the swing. There are reasons for those somewhat random small groups but they are typically very tune sensitive or just won't repeat...err, hold tune. I like setting 2 or 10 of that test with 2 being at top and 10 at bottom. In SR CF, I'd probably go with 10 because the next couple of groups are absolute textbook as far as what I look for along with poi being at bottom confirming being at an anti-node, which IS what we want. See how one thing confirms the other? For LR and RF, I'd go with 2 because of PC and not having control of ammo velocity ES with rf. PC can only happen on the upswing. I like 10 because it speaks to me, loud and clear, more so than 2 but will be more sensitive to ES of the ammo and at distance. Those things are of little consequence in SR CF but they are in RF and LR.

One last thing...the test also tells me which way to move the tuner if I see specific group shapes as tune goes away. See 10, 11 and 12. Beautiful, textbook example of what I look for and preach...for about 15 years now. 2,3 and 4 are NOT a wide spot. They are an example of the gun creeping out of tune but still shooting just well enough to lose.

Why would you want to be at the anti-node when it's the node that's stable? I must be missing something???

 

[gunsandgunsmithing]

Why would you want to be at the anti-node when it's the node that's stable? I must be missing something???

View attachment 1581375

Couple of reasons but one..there have been several behind the muzzle tuners utilized over the years now. Forget rf vs cf. Those tuners proved to work. And, in order to move a node to the end of a cantilevered beam, barrel..the tuner must extend beyond the crown or end of the beam. This is not opinion but physics. Also, vibration analysis confirms least angular muzzle movement at tp and bottom, or anti nodes. We can delve deeply into this but it's not necessary due to knowing that behind the muzzle tuners can work the same way at affecting tune.
Unfortunately, Mr Calfee just passed away and is the one who incorrectly started this notion several years ago. Science has simply proven it to be false without bias.

 

[CharlieNC]

Why would you want to be at the anti-node when it's the node that's stable? I must be missing something???

View attachment 1581375

That's not what the muzzle does. Hold a ruler by one end on a table and strike the free end to observe, and with a barrel time around 1.5msec the bullet is gone before these low frequencies captured by high speed camera set in.

 

[Straightshooter1]

Couple of reasons but one..there have been several behind the muzzle tuners utilized over the years now. Forget rf vs cf. Those tuners proved to work. And, in order to move a node to the end of a cantilevered beam, barrel..the tuner must extend beyond the crown or end of the beam. This is not opinion but physics. Also, vibration analysis confirms least angular muzzle movement at tp and bottom, or anti nodes. We can delve deeply into this but it's not necessary due to knowing that behind the muzzle tuners can work the same way at affecting tune.
Unfortunately, Mr Calfee just passed away and is the one who incorrectly started this notion several years ago. Science has simply proven it to be false without bias.

That's not what the muzzle does. Hold a ruler by one end on a table and strike the free end to observe, and with a barrel time around 1.5msec the bullet is gone before these low frequencies captured by high speed camera set in.

Like this:

 

[gunsandgunsmithing]

Like this:

Just do a little research on the subject. It's out there for those that want to know details. Most people just wanna know how to best utilize a tuner, much more so than debating how they do it. Bottom line, a node can NOT be moved to the end of a cantilevered beam UNLESS the tuner, in this case, extends beyond the crown. Which most do..now. There was a time when the majority of commercial tuners were behind the muzzle...yet they worked at tuning a rifle. These threads almost always turn into shit shows over the details..that most people don't even care about. I will just ask that you do the research before doubting what I have researched extensively before posting and before making tuners.

They all work on the same principle. So I won't get into selling anything but more than anything, just describe my tuning method and why it works, based on lots of years of testing, both in real life and lab environments. We can all choose our own method and theorize but testing is how we know stuff. Research resources are out there but it's gonna take anyone a fair amount of time finding applicable info. One thing that vibration analysis proved to me defies physics...on the surface at least. That's that physics teaches us that a weight on the end of the bbl will REDUCE amplitude. This is true...over time. But in the time we are worried about is that short period while the bullet is still in the bbl. Analysis proved an INCREASE in amplitude during this time. Different bbls, were different amounts..fwiw.

 

[JimSC]

If this is in regard to the test center I suggest either test using the owners preferred tuner setting if one has been established one or the owner agrees test without the tuner.

A quck Google will give you about a dozen different methods of doing the initial setting and I am sure they all worked for the guy making the video. I learned Gunsandgunsmithing's method on a centerfire and carried it over to rimfire with a couple of minor changes. I am not going to speculate on the theory part, I honestly don't care. If something works ,it works. Now if I could just learn to read wind as consistently as the rifle shoots in low wind conditions I would be ok. The one thing I would stress is to fine tune in 1 or 2 click increments, "a lil dab will do ya" as that ancient commercial said

I do 3 round test groups and concentrate on removing the vertical spread. My attachment shows 3 different ammos all shot through the Vudoo singleshot with a 26 inch Benchmark barrel and a Harrel tuner, with the top 2 using a J Pappas noodle with slider. All exhibit a sine wave effect which repeats every 12 - 14 clicks

Just my opinion and very limited experiance but tuners do not fix flyers. When set correctly they can and will reduce the circuler error probable. I have succeed doing with 6 rifles I tried it with.

I had 2 where the tuner seemed to have little or no effect. They were both 16 inch bull barrel .22 LR, a CZ Varmint and a Kidd. I think the were just too short and stiff to vibrate much but that is pure opinion, not proven. Easiest rifle was a old 40X with a reverse taper barrel. I think the earlier smiths were onto something, those barrels vibrated like a violin string with all that weight toward the muzzle.

This barrel is chambered for Lapua. The best I could get it to shoot any flavor Eley or RWS was in the high 3's and low 4's on the vertical spread. With SK and Lapua 0's and 1's were common and chambering is so much easier. What I am trying to say that the rifle will shoot a preferred ammo without flyers with or without the tuner attached and tuner will not help with the flyer situation. Sorry for being so long winded

 

[Straightshooter1]

Just do a little research on the subject. It's out there for those that want to know details. Most people just wanna know how to best utilize a tuner, much more so than debating how they do it. Bottom line, a node can NOT be moved to the end of a cantilevered beam UNLESS the tuner, in this case, extends beyond the crown. Which most do..now. There was a time when the majority of commercial tuners were behind the muzzle...yet they worked at tuning a rifle. These threads almost always turn into shit shows over the details..that most people don't even care about. I will just ask that you do the research before doubting what I have researched extensively before posting and before making tuners.

They all work on the same principle. So I won't get into selling anything but more than anything, just describe my tuning method and why it works, based on lots of years of testing, both in real life and lab environments. We can all choose our own method and theorize but testing is how we know stuff. Research resources are out there but it's gonna take anyone a fair amount of time finding applicable info. One thing that vibration analysis proved to me defies physics...on the surface at least. That's that physics teaches us that a weight on the end of the bbl will REDUCE amplitude. This is true...over time. But in the time we are worried about is that short period while the bullet is still in the bbl. Analysis proved an INCREASE in amplitude during this time. Different bbls, were different amounts..fwiw.

It's not really about "doubting" what you're saying, it more that I tend to be a skeptic about everything and look to clearly understanding what's being said.

While I put a lot of value on extensive research, I also know that science is not absolute. Continued research often reveals things we haven't thought about before.

Keeping the weeds out of the garden takes some effort.

Thank you for your response. It helps me as I think it will others too.

 

[gunsandgunsmithing]

It's not really about "doubting" what you're saying, it more that I tend to be a skeptic about everything and look to clearly understanding what's being said.

While I put a lot of value on extensive research, I also know that science is not absolute. Continued research often reveals things we haven't thought about before.

Keeping the weeds out of the garden takes some effort.

Thank you for your response. It helps me as I think it will others too.

I totally understand, but respectfully, testing yourself is the only way to weed out doubt. Not many have done even a small percentage of what I have regarding testing on the subject of tuners but I welcome any and all that wanna do the same or similar. Not many will do it, though. Doesn't stop some from having strong opinions. Not speaking of you with that comment but in general.
edit...Charlie has done some similar testing and I don't recall our conclusions deviating much if any.

 

[JimSC]

here is a pic of my workup target for a Harrels, which sort of shows how I go about it. I got lucky and a node that shot a .122 vertical was on 400 so I followed my gut and did a fine tune. 500 was smaller overall but I could only adjust down from there. The middle bottom row was playing with the slider on the noodle and the bottom was 5 - 10 shot groups. Rifle is a Remington 40X, unknown barrel and laminated wood stock, SK Pistol Match Special ammo

edit - Just sitting here looking at that target I could have probably found a tune starting at 500, 400, 100 or 0. They all had really small verticals.

 

[misser]

tuner test works for me. other groupings were much bigger

 

[gunsandgunsmithing]

tuner test works for me. other groupings were much bigger

What were you looking for, specifically? Clearly, it made the group bigger and smaller. Nothing wrong with tuning for small groups until conditions or lots change and you don't get small groups from it any more. The trick is not getting it to shoot small but to keep it shooting small. At least IMHO

 

[JimSC]

at least from 50F to 90F using half a dozen flavors of ammo I have not seen a need to change tuner setting more than three or four clicks to tune. The other day was about 90F and the Vudoo was shooting set at 395 and 2nd slider hole with SK gray box

 

[gunsandgunsmithing]

at least from 50F to 90F using half a dozen flavors of ammo I have not seen a need to change tuner setting more than three or four clicks to tune. The other day was about 90F and the Vudoo was shooting set at 395 and 2nd slider hole with SK gray box

Cool! Still a change and that's what I've been preaching. Good on you for testing in small increments. They do matter! Can't seem to get a lot of people to move small. Even 4 marks with a given lot is a big swing at tune, based only on condition changes, ie, your 50-90° example. In fact, it's what I'd expect for a 40-45 degree swing.

 

[SteveOak]

What I see in your target is the same sine wave as this from gunsandgunsmithing:
View attachment 1581231

And it still seems to me that the best place to be with a tuner is at the node of the wave.

Do you really mean node?

 

[misser]

What were you looking for, specifically? Clearly, it made the group bigger and smaller. Nothing wrong with tuning for small groups until conditions or lots change and you don't get small groups from it any more. The trick is not getting it to shoot small but to keep it shooting small. At least IMHO

yep thats the nice thing about a tuner .one day its right the next its a click up or a click down to keep'em small

 

[Hi-NV Shooter]

John,

How are you going to set the rifle up for this tuner testing in a jig or will you shoot it like you do in matches?
replicating how you will shoot it will also have an effect on tuning. recoil impulse plays a big part as it will have some effect on barrel movement. too fast a rearward movement or too slow can change tuner setting results.
also are you looking for a general process for tuning any type of rifle or do you have a specific discipline. for the longest time tuners/tuning in rimfire shooting was more for benchrest. but now even NRL and PRS rifles are using them.
I hope you find a method that will work for you. it will be interesting on what you see in a tunnel environment versus most who tune outdoors.

Lee

 

[Straightshooter1]

Do you really mean node?

Yes, I mean node.

I say that because as @gunsandgunsmithing says here, the tuners we use are mounted in front of the muzzle; meaning the bullet is released before it exits the tuner (in my case, I use a tuner-break). The tuner has added length to the cantilever, changing the harmonics and maybe even the harmonic mode and where the node is. My thinking is that the change in the harmonic that the tuner does moves the node towards the muzzle where the bullet is released, which could not happen without the lengthening of the cantilever (barrel + tuner). And can be further moved according the the tuner adjustments. The bullet release point doesn't change (barrel length stays the same) with the lengthening of the cantilever by the tuner, the location of the node does. Anyhow, this is my current thinking.

Example of where the node is for Mode 2 of this cantilever and its frequency:


Different modes shapes for the different frequencies:

 

[JimSC]

Cool! Still a change and that's what I've been preaching. Good on you for testing in small increments. They do matter! Can't seem to get a lot of people to move small. Even 4 marks with a given lot is a big swing at tune, based only on condition changes, ie, your 50-90° example. In fact, it's what I'd expect for a 40-45 degree swing.

I suspect different ammos have slightly differnt velocities of course and temps but I also believe most standard velocity .22LR is close in velocity and not near as temperature sensitive as some of the centerfire powders are. I now have a Garmin and a couple of cases of decent shooting mid priced ammo and this thread reminded me of a itch I had last spring but never scratched. I need to start a spreadsheet with one lot and track it through the winter and spring logging all the enviromentals just to see if I can spot any trends. It's going to be around 90F before noon Monday with 4 mph winds so that would be a good day to start that project. I suspect the slider tube on the noodle affects the velocity also so that is another project I can do at the same time

 

[gunsandgunsmithing]

I suspect different ammos have slightly differnt velocities of course and temps but I also believe most standard velocity .22LR is close in velocity and not near as temperature sensitive as some of the centerfire powders are. I now have a Garmin and a couple of cases of decent shooting mid priced ammo and this thread reminded me of a itch I had last spring but never scratched. I need to start a spreadsheet with one lot and track it through the winter and spring logging all the enviromentals just to see if I can spot any trends. It's going to be around 90F before noon Monday with 4 mph winds so that would be a good day to start that project. I suspect the slider tube on the noodle affects the velocity also so that is another project I can do at the same time

Actually, there are a couple of guys on a rf forum that have been doing just that. Most often, there is a small increase in speed as temps rise but there was at least one example given where it dropped slightly..one iirc.

The other thing and it's big, the pressure curve can change while the final muzzle velocity stays the same. Yes, less powder and pretty awesome case efficiency of a 22lr does make changes smaller than in cf. The biggest variable is the one that is a chemical reaction. That's smokeless powder turning from a solid to a gas.