Tuner Test - results confusing

[Ned Ludd]

Here is more detailed information about the tuner (i.e. increments, Erik's process to set the tuner):



As can be seen from the image, the tuner increments go from 0 to 50, being numbered every 5 on the tuner body. Further, the thread pitch is 20 TPI, indicating 0.050" linear movement per turn, and 0.001" linear movement per single increment/hashmark.





FWIW - I have several of Erik's original tuners. One major difference between the two versions is that the original tuner has 25 increments per full turn, or exactly half the number found on the V2. Other differences are largely confined to the external appearance and the mechanism by which friction is created to prevent random [unwanted] turning of the device. Functionally, they should work exactly the same with respect to tuning and barrel harmonics.

From what the OP described, I can see a few potential differences between what I perceive should be the "correct" method for testing per Erik's instructions, and the way it was actually carried out. The instructions indicate the tuner should be installed ~ flush with the muzzle, an index mark created, and be turned outward during the tuning process. If I understand the OP correctly, the tuner was turned inward from the index mark. That probably shouldn't make a huge difference in finding a "tune" window as long as there was sufficient travel to turn the tuner inward at least one full turn. The reason for turning it outward is that there may not be sufficient inward travel depending on the installation process. Regardless, one can find a tune window twirling the tuner in either direction.

However, the reason I mentioned the suggested installation and process for setting the tuner is because of some more recent comments and groups posted by the OP, where the tuner apparently was not attached. The idea is to carry out what most would call "standard load development practices" initially, with the tuner screwed down to the "0" setting. In other words, the approach should be to set the tuner at "0", then carry out charge weight and seating depth testing until a well-tuned load has been achieved before carrying out a tuner test. From the more recent posts regarding groups with the tuner not attached, it is unclear to me exactly how the original tuner testing was carried out; i.e. was the load developed with the tuner attached and screwed down to "0"? Or with the tuner not attached? I raise these questions because it might make a difference in how the final results manifest during the testing process.

My experience with Erik's original tuner design is that one should observe at least one optimal tune window within a single rotation. In my hands, such a window may be as much as 5-7 single increments wide as shown in the attached tuner test image, but that would be totally dependent on the cartridge/load/rifle setup. Although I have carried out numerous tuner tests that generated similar results, the test shown below is one where the results were quite clear and that I actually could find the image file to post herein. Below the fired groups is a graph of Group Size versus Tuner Setting as an example, where I used three-shot groups and moved the tuner 3 increments (out of 25 total per turn) per group, for a total of [almost] two complete turns. As can be seen from the image, the "optimal" window (~15-21) also occurs during the second turn of the tuner, at very close to the equivalent point in the rotation cycle as was observed on the first turn.



My point here is that moving the tuner 5 increments between each group as outlined in the testing procedure may be too coarse. I view this situation as not totally unlike seating depth testing, where using too large or coarse a seating depth increment during the testing process can sometimes lead to completely missing seating depth optima. It may be worth repeating the tuner test, being sure the load is well-tuned/developed, with the tuner attached and set at "0", then using increments of 2.5 per group, rather than 5. To be sure, repeating the test in that manner won't necessarily guarantee different results, but at least it will be unlikely that any potentially optimized settings won't be missed. I would also add to this that it is highly desirable to have the best (i.e. mildest) possible conditions during the test, and that if a shot is pulled by the shooter as evidenced via the reticle, it must be recorded during testing. If you think you pulled a shot or were caught by a wind change even a couple times during the testing and didn't record it, it can make the final results exceedingly difficult to interpret.

 

[SG4247]

Uep,
Thats what I did, except I went clockwise or toward the muzzle 5 marks at a time from flush. If you go counter clockwise, that would potentially expose the sealing (friction) o-ring, to muzzle blast.

Basic load worked up was in advance of installing the tuner, as shown by the December target in previous posts.

 

[gunsandgunsmithing]

Here is more detailed information about the tuner (i.e. increments, Erik's process to set the tuner):

View attachment 1403954

As can be seen from the image, the tuner increments go from 0 to 50, being numbered every 5 on the tuner body. Further, the thread pitch is 20 TPI, indicating 0.050" linear movement per turn, and 0.001" linear movement per single increment/hashmark.


View attachment 1403955


FWIW - I have several of Erik's original tuners. One major difference between the two versions is that the original tuner has 25 increments per full turn, or exactly half the number found on the V2. Other differences are largely confined to the external appearance and the mechanism by which friction is created to prevent random [unwanted] turning of the device. Functionally, they should work exactly the same with respect to tuning and barrel harmonics.

From what the OP described, I can see a few potential differences between what I perceive should be the "correct" method for testing per Erik's instructions, and the way it was actually carried out. The instructions indicate the tuner should be installed ~ flush with the muzzle, an index mark created, and be turned outward during the tuning process. If I understand the OP correctly, the tuner was turned inward from the index mark. That probably shouldn't make a huge difference in finding a "tune" window as long as there was sufficient travel to turn the tuner inward at least one full turn. The reason for turning it outward is that there may not be sufficient inward travel depending on the installation process. Regardless, one can find a tune window twirling the tuner in either direction.

However, the reason I mentioned the suggested installation and process for setting the tuner is because of some more recent comments and groups posted by the OP, where the tuner apparently was not attached. The idea is to carry out what most would call "standard load development practices" initially, with the tuner screwed down to the "0" setting. In other words, the approach should be to set the tuner at "0", then carry out charge weight and seating depth testing until a well-tuned load has been achieved before carrying out a tuner test. From the more recent posts regarding groups with the tuner not attached, it is unclear to me exactly how the original tuner testing was carried out; i.e. was the load developed with the tuner attached and screwed down to "0"? Or with the tuner not attached? I raise these questions because it might make a difference in how the final results manifest during the testing process.

My experience with Erik's original tuner design is that one should observe at least one optimal tune window within a single rotation. In my hands, such a window may be as much as 5-7 single increments wide as shown in the attached tuner test image, but that would be totally dependent on the cartridge/load/rifle setup. Although I have carried out numerous tuner tests that generated similar results, the test shown below is one where the results were quite clear and that I actually could find the image file to post herein. Below the fired groups is a graph of Group Size versus Tuner Setting as an example, where I used three-shot groups and moved the tuner 3 increments (out of 25 total per turn) per group, for a total of [almost] two complete turns. As can be seen from the image, the "optimal" window (~15-21) also occurs during the second turn of the tuner, at very close to the equivalent point in the rotation cycle as was observed on the first turn.

View attachment 1403965

My point here is that moving the tuner 5 increments between each group as outlined in the testing procedure may be too coarse. I view this situation as not totally unlike seating depth testing, where using too large or coarse a seating depth increment during the testing process can sometimes lead to completely missing seating depth optima. It may be worth repeating the tuner test, being sure the load is well-tuned/developed, with the tuner attached and set at "0", then using increments of 2.5 per group, rather than 5. To be sure, repeating the test in that manner won't necessarily guarantee different results, but at least it will be unlikely that any potentially optimized settings won't be missed. I would also add to this that it is highly desirable to have the best (i.e. mildest) possible conditions during the test, and that if a shot is pulled by the shooter as evidenced via the reticle, it must be recorded during testing. If you think you pulled a shot or were caught by a wind change even a couple times during the testing and didn't record it, it can make the final results exceedingly difficult to interpret.

Not knocking anything or anyone, as there's more than one way and we should all do what works best for us. That said, I think you'd benefit from even smaller increments and there is no physical reason that I know of that will create a wide area relative to tuner travel/tune. We're changing what is essentially a constant and each adjustment should have a quantifiable value on the target. Your target doesn't show what I look for to read it very well at all, which is why I think even smaller increments will be beneficial to you. My test is about just that...quantifying the value of each increment. Without knowing that, we're guessing. Simple as that. Sure, we can land on a sweet spot but the real value of a tuner is knowing how to reliably bring it back into full tune when it goes out. Case in point...your target. Tuner setting 39 looks great but lets say it goes straight vertical on ya. Now what? Which way and how far would you move it to bring it back to your 39 group? I want to see that answer in my test target. I think you'll see it if you move 1 mark at a time....maybe two. Pretty easy to try, just fire about 5 three shot groups moving it 1 mark at a time. If 1 mark is too fine on his tuner, you'll see essentially no change in group shape. Maybe I'll edit my signature line to say something like...The most common mistake people make with tuners is moving too far at a time. I sound like a broken record with that statement but it's very true.

I like Erik and I have no bone to pick here but apparently we disagree on how far to move it at a time....and that's ok. It'd be pretty boring if we all agree on everything.

 

[gunsandgunsmithing]

Uep,
Thats what I did, except I went clockwise or toward the muzzle 5 marks at a time from flush. If you go counter clockwise, that would potentially expose the sealing o-ring, to muzzle blast.

Basic load worked up was in advance of installing the tuner, as shown by the December target in previous posts.

Tune repeats over and over. I prefer to do my load work with the tuner on but it works either way. I start with mine 1/2 to a full turn out and move it outward during the test. A half turn from bottomed on my standard tuner is more than enough adjustment in that direction to bring it back, even from completely out of tune.

 

[whatwind?]

Yes, 40 degree Shehane. 600 on the bbl.

Testing in 35 degrees, with a 28.5” bbl.

It will go much faster if needed.

Lean on it, at least get to 2880

 

[Ned Ludd]

Not knocking anything or anyone, as there's more than one way and we should all do what works best for us. That said, I think you'd benefit from even smaller increments and there is no physical reason that I know of that will create a wide area relative to tuner travel/tune. We're changing what is essentially a constant and each adjustment should have a quantifiable value on the target. Your target doesn't show what I look for to read it very well at all, which is why I think even smaller increments will be beneficial to you. My test is about just that...quantifying the value of each increment. Without knowing that, we're guessing. Simple as that. Sure, we can land on a sweet spot but the real value of a tuner is knowing how to reliably bring it back into full tune when it goes out. Case in point...your target. Tuner setting 39 looks great but lets say it goes straight vertical on ya. Now what? Which way and how far would you move it to bring it back to your 39 group? I want to see that answer in my test target. I think you'll see it if you move 1 mark at a time....maybe two. Pretty easy to try, just fire about 5 three shot groups moving it 1 mark at a time. If 1 mark is too fine on his tuner, you'll see essentially no change in group shape. Maybe I'll edit my signature line to say something like...The most common mistake people make with tuners is moving too far at a time. I sound like a broken record with that statement but it's very true.

I like Erik and I have no bone to pick here but apparently we disagree on how far to move it at a time....and that's ok. It'd be pretty boring if we all agree on everything.

I have done exactly what you suggested, but the data aren't shown on this particular image. I lost a number of previous tuner setting data sets that were stored on a computer that was stolen and were not backed up. I used this data set/image here as an example for the OP only, largely because it was one for which I still had the final image stored on a different computer. With respect to tuner setting #39 in the image above, I no longer even attempt a second turn of the tuner. In my hands, in simply isn't necessary and I will see what I need to see within a single full turn of the tuner. I now test starting with the tuner set at zero, then using 2 increments per group to cover one full turn of the tuner. Then I go back and cover the odd number settings around/within whatever appears to be a solid window to finish off the test. In other words, I try to test every at tuner increment to completely cover the optimal window. What I can tell you is that I almost always observe a single well-defined and fairly wide window (i.e. at least 4-7 increments wide out of 25 total increments per turn), where the groups are minimal in size. Further, this window can be readily reproduced on different days.

It's important to note that this example was solely to illustrate something for the OP. It's also worth noting that I shoot F-TR. I do all of my load development off the bipod exactly as I shoot in matches, so there is a limit to how "fine" my typical results will ever be. I'm sure I could do much better if I was using a front rest, but I don't shoot that way in matches and I'm not going use one for load development. In any event, I'm not interested in using a tuner setting that might be only one or two increments wide. I don't think such a narrow setting is useful, or even advisable, for the typical F-Class shooter because of how we load for matches in advance, and shoot long strings of under a fairly wide range of conditions, over a time period where changing wind conditions are likely to be the limiting source of error by far. I think you and I may disagree on that aspect of setting the tuner, which is fine, no worries. What I'm looking for is a nice fat window that exhibits minimal dispersion, and requires minimal adjustment across a range of conditions. The good news is that I have generally found exactly what I am looking for during past tuner testing with the rifles I use that have tuners. I typically load to the center of that window for matches. As long as I maintain consistent muzzle velocity across the range of conditions I encounter at different matches, this has held up well.

So, what I described seems a fairly different approach than what I understand BR shooters use. That's fine, to each what they have found to work in their hands. In F-Class, it is not always the shooter that has the tightest shooting and most precise rifle/load that wins, but the one that reads the wind most consistently. In other words, it is not always about pure accuracy/precision. My point is that what works well for one discipline may not always be the best, or even desirable for another. As an F-TR shooter, I don't want to have to make anything greater than a single increment or two adjustment in either direction with the tuner at a match, and only then if I see something happening on the target that I really don't like, such as unacceptable vertical. Fortunately, this approach has worked well so far, even if I may be leaving something on the table with respect to utilizing the full capabilities of the tuner. I just don't want to have to make any major adjustments with it during a match, and as long as I can maintain consistent velocity for different conditions using charge weight, I haven't found it necessary to do so. I can imagine this approach may not work with every cartridge/bullet/powder combination used by F-Class shooters. Perhaps I am just fortunate or lucky to routinely observe these nice fat optimal tuner windows with the rifles and cartridges I'm using. Nonetheless, if one actually does observe these nice wide tuner windows, it appears that it takes a pretty marked change in conditions to cause the optimal tuner setting to move outside that window, at least in my hands.

 

[gunsandgunsmithing]

I have done exactly what you suggested, but the data aren't shown on this particular image. I lost a number of previous tuner setting data sets that were stored on a computer that was stolen and were not backed up. I used this data set/image here as an example for the OP only, largely because it was one for which I still had the final image stored on a different computer. With respect to tuner setting #39 in the image above, I no longer even attempt a second turn of the tuner. In my hands, in simply isn't necessary and I will see what I need to see within a single full turn of the tuner. I now test starting with the tuner set at zero, then using 2 increments per group to cover one full turn of the tuner. Then I go back and cover the odd number settings around/within whatever appears to be a solid window to finish off the test. In other words, I try to test every at tuner increment to completely cover the optimal window. What I can tell you is that I almost always observe a single well-defined and fairly wide window (i.e. at least 4-7 increments wide out of 25 total increments per turn), where the groups are minimal in size. Further, this window can be readily reproduced on different days.

It's important to note that this example was solely to illustrate something for the OP. It's also worth noting that I shoot F-TR. I do all of my load development off the bipod exactly as I shoot in matches, so there is a limit to how "fine" my typical results will ever be. I'm sure I could do much better if I was using a front rest, but I don't shoot that way in matches and I'm not going use one for load development. In any event, I'm not interested in using a tuner setting that might be only one or two increments wide. I don't think such a narrow setting is useful, or even advisable, for the typical F-Class shooter because of how we load for matches in advance, and shoot long strings of under a fairly wide range of conditions, over a time period where changing wind conditions are likely to be the limiting source of error by far. I think you and I may disagree on that aspect of setting the tuner, which is fine, no worries. What I'm looking for is a nice fat window that exhibits minimal dispersion, and requires minimal adjustment across a range of conditions. The good news is that I have generally found exactly what I am looking for during past tuner testing with the rifles I use that have tuners. I typically load to the center of that window for matches. As long as I maintain consistent muzzle velocity across the range of conditions I encounter at different matches, this has held up well.

So, what I described seems a fairly different approach than what I understand BR shooters use. That's fine, to each what they have found to work in their hands. In F-Class, it is not always the shooter that has the tightest shooting and most precise rifle/load that wins, but the one that reads the wind most consistently. In other words, it is not always about pure accuracy/precision. My point is that what works well for one discipline may not always be the best, or even desirable for another. As an F-TR shooter, I don't want to have to make anything greater than a single increment or two adjustment in either direction with the tuner at a match, and only then if I see something happening on the target that I really don't like, such as unacceptable vertical. Fortunately, this approach has worked well so far, even if I may be leaving something on the table with respect to utilizing the full capabilities of the tuner. I just don't want to have to make any major adjustments with it during a match, and as long as I can maintain consistent velocity for different conditions using charge weight, I haven't found it necessary to do so. I can imagine this approach may not work with every cartridge/bullet/powder combination used by F-Class shooters. Perhaps I am just fortunate or lucky to routinely observe these nice fat optimal tuner windows with the rifles and cartridges I'm using. Nonetheless, if one actually does observe these nice wide tuner windows, it appears that it takes a pretty marked change in conditions to cause the optimal tuner setting to move outside that window, at least in my hands.

By all means, do what works for you. I would sincerely like to hear your or anyone else's opinion on WHY or HOW there should be areas of width in terms of tuner travel. I've never been able to reproduce them when I've seen it happen, predictably. Seeing it with powder charge is expected, but from a physics standpoint, it doesn't make sense that it happens for you with a tuner. I'm not saying it doesn't but would surely like to know more about why and how it does for you. I take your word for it and I value what you say but I've only seen reason why it should not happen and never anything to explain why it should. Dampening comes to mind and dampening qualities are a big asset to tuner design, IMHO. That's why mine is made the way it is vs a solid mass. I tested that aspect quite a bit on paper and to some extent with vibration analysis. We do agree though that small adjustments can matter. I never move more than a mark or two at a match...or really ever unless I change something about the load. In which case, 4-5 marks(max) will typically take it from completely out of tune to back into perfect tune.

Again, I value your opinion and I take you at your word. I just wish I understood that aspect better. It's also why I don't make blanket statements regarding how to use ANY tuner. There are differences and I try to stay in my lane and be specific about what I've found regarding MY tuner. What I posted was based on your target and the target is what tells me that I'd move in smaller increments than that test target.

In the end, it's ok to disagree, right? Erik is a good guy and I'm sure he's selling a quality product. No doubt here about that. And from reading your post, we agree much more than not anyway.

 

[jackieschmidt]

I have done exactly what you suggested, but the data aren't shown on this particular image. I lost a number of previous tuner setting data sets that were stored on a computer that was stolen and were not backed up. I used this data set/image here as an example for the OP only, largely because it was one for which I still had the final image stored on a different computer. With respect to tuner setting #39 in the image above, I no longer even attempt a second turn of the tuner. In my hands, in simply isn't necessary and I will see what I need to see within a single full turn of the tuner. I now test starting with the tuner set at zero, then using 2 increments per group to cover one full turn of the tuner. Then I go back and cover the odd number settings around/within whatever appears to be a solid window to finish off the test. In other words, I try to test every at tuner increment to completely cover the optimal window. What I can tell you is that I almost always observe a single well-defined and fairly wide window (i.e. at least 4-7 increments wide out of 25 total increments per turn), where the groups are minimal in size. Further, this window can be readily reproduced on different days.

It's important to note that this example was solely to illustrate something for the OP. It's also worth noting that I shoot F-TR. I do all of my load development off the bipod exactly as I shoot in matches, so there is a limit to how "fine" my typical results will ever be. I'm sure I could do much better if I was using a front rest, but I don't shoot that way in matches and I'm not going use one for load development. In any event, I'm not interested in using a tuner setting that might be only one or two increments wide. I don't think such a narrow setting is useful, or even advisable, for the typical F-Class shooter because of how we load for matches in advance, and shoot long strings of under a fairly wide range of conditions, over a time period where changing wind conditions are likely to be the limiting source of error by far. I think you and I may disagree on that aspect of setting the tuner, which is fine, no worries. What I'm looking for is a nice fat window that exhibits minimal dispersion, and requires minimal adjustment across a range of conditions. The good news is that I have generally found exactly what I am looking for during past tuner testing with the rifles I use that have tuners. I typically load to the center of that window for matches. As long as I maintain consistent muzzle velocity across the range of conditions I encounter at different matches, this has held up well.

So, what I described seems a fairly different approach than what I understand BR shooters use. That's fine, to each what they have found to work in their hands. In F-Class, it is not always the shooter that has the tightest shooting and most precise rifle/load that wins, but the one that reads the wind most consistently. In other words, it is not always about pure accuracy/precision. My point is that what works well for one discipline may not always be the best, or even desirable for another. As an F-TR shooter, I don't want to have to make anything greater than a single increment or two adjustment in either direction with the tuner at a match, and only then if I see something happening on the target that I really don't like, such as unacceptable vertical. Fortunately, this approach has worked well so far, even if I may be leaving something on the table with respect to utilizing the full capabilities of the tuner. I just don't want to have to make any major adjustments with it during a match, and as long as I can maintain consistent velocity for different conditions using charge weight, I haven't found it necessary to do so. I can imagine this approach may not work with every cartridge/bullet/powder combination used by F-Class shooters. Perhaps I am just fortunate or lucky to routinely observe these nice fat optimal tuner windows with the rifles and cartridges I'm using. Nonetheless, if one actually does observe these nice wide tuner windows, it appears that it takes a pretty marked change in conditions to cause the optimal tuner setting to move outside that window, at least in my hands.

Since I shoot both Short Range Group and Score, I can give you a little perspective on how I use my tuner.

Like many Short range Shooters, I have a very specific load combination that I know will shoot in a Bartlien or Krieger cut rifled barrel. Keep in mind, I make both my own 68 grn 6mm and 112 grn 30 caliber bullet. So that is a constant I can rely on. I also use N133 exclusively in my 6PPC and Alternate between H4198 and LT30 in my 30BR.

When I install a new barrel on my 6PPC Group Rifle I put that load combo in and after break in, I shoot two shot groups, adjusting the tuner untill those two are together. I then shoot three shot groups and fine tune untill I see a competitive agging capability.

If this holds for 5 shot groups, it is ready. However, at a Match,, (we load at the Match after every group), if I sense the tune is going away, I will tweak the powder charge just a little rather than move the tuner. I do this because of a few of the weird quirks that N133 exhibits as weather conditions change.

On my 30 BR Score Rifle, I follow the same procedure except I will turn the tuner if I feel like the Rifle is getting way to wind sensitive in the horizontal. I would much rather have a bullet hole of vertical than fight a condition that seems to move the bullet left and right more than my wind reading abilities.

Keep in mind, in Score, unlike Group, you don’t get any free shots.

My tuner is on a 36 TPI With a dampener. I adhere to Mike‘s credo that most people use way too wide of adjustments. A full quarter turn is just .007 advance, but I usually find the sweet spot within just a couple of thousandths advance. If my Score Rifle is shooting dead flat, I can kick a tad of vertical in it with as little as .002 advance or retract If I get caught in a dead across wind that makes it too difficult to keep it on the X.

With the Score Rifle, I will change the tuner and rarely change anything else. With the Group Rifle, I rarely change the tuner and rely on small powder changes to keep things competitive.

As a note, I know Short Range Shooters who use a tuner to find the optimum vibration node in their Barrel and never move it again, relying on the conventional methods to keep the Rifle agging at a competitive level.

 

[SG4247]

On my 30 BR Score Rifle, I follow the same procedure except I will turn the tuner if I feel like the Rifle is getting way to wind sensitive in the horizontal. I would much rather have a bullet hole of vertical than fight a condition that seems to move the bullet left and right more than my wind reading abilities.

This blows my mind. I’ve read/heard other SR BR shooters mention this as well.

I’d like to see this done in practice. I truly don’t understand it.

 

[Ccrider]

Great post. Op, being new to this I will say something that has not been said. Until and unless you have your rifle tuned, twisting the tuner is not going to get you there.

If you want help, show your tuning targets. Explain how you got to what you call tune. Then these guys can make sense of where you are with the tuner. Remember, for several of these guys, in tune is agging in the 1s for several repeated five shot groups. And, they do this repeatedly and expect and require it in their competition guns.

Otherwise, you are getting good general information that want get you very far unless you luck into it, much like a wallet group that you can’t repeat.

 

[Ned Ludd]

By all means, do what works for you. I would sincerely like to hear your or anyone else's opinion on WHY or HOW there should be areas of width in terms of tuner travel. I've never been able to reproduce them when I've seen it happen, predictably. Seeing it with powder charge is expected, but from a physics standpoint, it doesn't make sense that it happens for you with a tuner. I'm not saying it doesn't but would surely like to know more about why and how it does for you. I take your word for it and I value what you say but I've only seen reason why it should not happen and never anything to explain why it should. Dampening comes to mind and dampening qualities are a big asset to tuner design, IMHO. That's why mine is made the way it is vs a solid mass. I tested that aspect quite a bit on paper and to some extent with vibration analysis. We do agree though that small adjustments can matter. I never move more than a mark or two at a match...or really ever unless I change something about the load. In which case, 4-5 marks(max) will typically take it from completely out of tune to back into perfect tune.

Again, I value your opinion and I take you at your word. I just wish I understood that aspect better. It's also why I don't make blanket statements regarding how to use ANY tuner. There are differences and I try to stay in my lane and be specific about what I've found regarding MY tuner. What I posted was based on your target and the target is what tells me that I'd move in smaller increments than that test target.

In the end, it's ok to disagree, right? Erik is a good guy and I'm sure he's selling a quality product. No doubt here about that. And from reading your post, we agree much more than not anyway.

FWIW - I make no attempt to explain or predict it, I just test and see what tuner settings shoot small . I've gone through cantilever beam theory, just enough to grasp the general idea. Any explanation or application of said theory to setting a tuner is far beyond my ability, or at least my mathematical skills. Fortunately, it's not that difficult to load rounds and empirically determine what setting(s) shoot small. As I noted previously, the use of a tuner in F-Class may be somewhat different both in intent and application than it would be for BR, because both the intent and methodology differ to some extent between the two disciplines. Shooting the smallest possible group is not the intent of F-Class, whereas dropping the fewest point is. That may seem a trivial difference, but it really isn't. In light of the potential changes in wind conditions that occur during the long strings of fire used in F-Class matches, having a rifle setup that shoots reasonably well over a wide range of conditions is much better (in my opinion) than a rifle setup that shoots super-teensy groups in specific conditions, but has to continually be tweaked to remain shooting at peak performance.

I can assure you that I am no expert whatsoever about tuner theory. I read what I can, and am able to comprehend most of it, but that's the limit. What I can tell you is that unless I make some significant shooter error(s) during the tuning process, I see a pretty good sized "optimal" window almost every time I test. Further, unless the conditions change markedly, that window remains solid for future trips to the range. In fairness, I haven't ever taken a rifle with a tuner to someplace like Raton, which is at much higher elevation, or places with major temperature differences, so I can't really say exactly where what I believe are the optimized tune windows I have identified during testing might start to change noticeably. Nonetheless, observing a nice fat tuner window in my hands seems to be the rule, not the exception. I know others that have had a similar experience. I also strongly suspect that may be the reason for Erik's suggested tuning process for users of his tuners, but I don't know that with certainty. I would certainly defer to your experience with tuners to characterize whether my experience using tuners might actually be the exception to the rule. If it is, I cannot explain why that would be other than perhaps the specific rifle/powder/bullet setups I am using in F-TR might have something to do with it. What I can say with some certainty is that if observing a [repeatable] nice fat optimal tuner window is not the way it's supposed to work, if more numerous small tuner optima perhaps only an increment or two wide are what one should be typically expect to observe during a tuner test, then I would personally find the use of a tuner to be almost a complete waste of time for an F-Class shooter. If super-fine, intricate, possibly even almost serendipitous tuner adjustments are supposed to be the norm when using a tuner, for me it would simply be a PITA for a variety of reasons, and I would just shoot a rifle without a tuner. I don't actually think that is the case, or at least that hasn't been my experience, but I could easily be wrong.

 

[jackieschmidt]

This blows my mind. I’ve read/heard other SR BR shooters mention this as well.

I’d like to see this done in practice. I truly don’t understand it.

If you go to enough Group Matches, you can see groups on the wailing wall that look like a straight across catepiller, especially at 200 yards in tough conditions. People will comment…..”well, at least it is in tune”.

Well, no it’s not. It’s in a horizontal tune, where try as you may, you cannot read the conditions well enough to keep it from horizontal stringing. You can cure this by tweaking the seating depth, or tweaking the tuner.

In Score, it’s the same way, especially if you are shooting in a predominately 90 degree condition. You will be missing that X at 3:00 o’clock or 9:00 because the rifle is naturally in a horizontal tune. You have to get the thing shooting round, tweeking the seating depth or adjusting the tuner will do the trick.

What you have done is getting a little vertical in the Rifle and relying on your condition reading to keep it on the X. In reality, you are locked into a nice round .200 agging capability which will get the job done.

Of course, sometimes you are just in the toilet and all of this whiz bang stuff just doesn’t seem to pan out. That is why most Benchrest Competitors will tell a new shooter that if you can’t stand NOT winning all the time, this ain’t the game for you.

 

[Ned Ludd]

Since I shoot both Short Range Group and Score, I can give you a little perspective on how I use my tuner.

Like many Short range Shooters, I have a very specific load combination that I know will shoot in a Bartlien or Krieger cut rifled barrel. Keep in mind, I make both my own 68 grn 6mm and 112 grn 30 caliber bullet. So that is a constant I can rely on. I also use N133 exclusively in my 6PPC and Alternate between H4198 and LT30 in my 30BR.

When I install a new barrel on my 6PPC Group Rifle I put that load combo in and after break in, I shoot two shot groups, adjusting the tuner untill those two are together. I then shoot three shot groups and fine tune untill I see a competitive agging capability.

If this holds for 5 shot groups, it is ready. However, at a Match,, (we load at the Match after every group), if I sense the tune is going away, I will tweak the powder charge just a little rather than move the tuner. I do this because of a few of the weird quirks that N133 exhibits as weather conditions change.

On my 30 BR Score Rifle, I follow the same procedure except I will turn the tuner if I feel like the Rifle is getting way to wind sensitive in the horizontal. I would much rather have a bullet hole of vertical than fight a condition that seems to move the bullet left and right more than my wind reading abilities.

Keep in mind, in Score, unlike Group, you don’t get any free shots.

My tuner is on a 36 TPI With a dampener. I adhere to Mike‘s credo that most people use way too wide of adjustments. A full quarter turn is just .007 advance, but I usually find the sweet spot within just a couple of thousandths advance. If my Score Rifle is shooting dead flat, I can kick a tad of vertical in it with as little as .002 advance or retract If I get caught in a dead across wind that makes it too difficult to keep it on the X.

With the Score Rifle, I will change the tuner and rarely change anything else. With the Group Rifle, I rarely change the tuner and rely on small powder changes to keep things competitive.

As a note, I know Short Range Shooters who use a tuner to find the optimum vibration node in their Barrel and never move it again, relying on the conventional methods to keep the Rifle agging at a competitive level.

Thanks for the explanation. I have read of similar approaches from others shooting BR disciplines. Not trying to step on anyone's toes here, but I don't believe such an approach would be easy or particularly fruitful during an F-Class match. The way F-Class matches are run and the fact that our ammo is fully loaded prior to the start of the match doesn't [at least in my mind] lend itself to that sort of approach for setting a tuner.

I have also seen for years those that claim a tuner can tune out sensitivity to wind deflection. If I understand those claims correctly, I believe what they are really doing is tuning out horizontal group dispersion, which is a load-specific phenomenon (i.e. internal ballistics), not wind dispersion, which is a phenomenon that is all about external ballistics. My understanding is that tuning by that method often comes at the expense of increased vertical dispersion. In other words, one would be making the group taller and narrower, thus apparently buying a little forgiveness to wind deflection. That isn't really what is happening as making a group spread pattern taller and narrower should in no way affect the actual wind deflection of a given bullet once it has left the muzzle, but that's what the perception seems to be.

I can see how re-setting a tuner by this approach would be useful in changing conditions during a BR match, but I also don't see how it would be realistic in an F-Class match with one possible caveat. One thing Erik noted in the instructions of how to set his original tuner was to observe which direction to either side of the optimal tune window the groups went vertical and which direction they went horizontal. That way, one could tweak the tuner setting by one or two clicks either direction from the middle of the window if they saw increasing vertical or horizontal dispersion during a match. However, one has to know what the behavior is in advance in order to do this, and they need to be certain about it, or points could be lost before any changes could be undone. I'm not saying I don't necessarily think it could be possible for F-Class shooters to twirl the tuner during a match, but one would have to be absolutely confident that what they were doing would have the desired result. These days, even one or two dropped points can be the difference between winning and not winning in an F-Class match. In my mind that means that tuner behavior needs to be absolutely clear and predictable, and I simply don't believe that it is at this point.

Again, I'm not trying to step on anyone's toes here, just making observations about the differences between shooting disciplines and posing the thought that if tuner behavior were actually written in stone, absolutely solid and perfectly understood, we probably wouldn't having this conversation.

 

[Titan]

...These days, even one or two dropped points can be the difference between winning and not winning in an F-Class match. In my mind that means that tuner behavior needs to be absolutely clear and predictable, and I simply don't believe that it is at this point...

Ned thank you for sharing your targets and experience. Just a few observations I think the set of 18 three shot groups, the average of the groups is .36 MOA and the SD of the groups was .13 MOA, 13 of the 18 groups are within one SD of the average this looks a lot like a normal distribution with a little more then 68% of the samples being within one SD of the average. To me they all look possibly the same and the product of random chance. Did you ever just leave the tuner at the best setting and shoot another 18 three shots groups and see if the average changed?

 

[Ned Ludd]

Ned thank you for sharing your targets and experience. Just a few observations I think the set of 18 three shot groups, the average of the groups is .36 MOA and the SD of the groups was .13 MOA, 13 of the 18 groups are within one SD of the average this looks a lot like a normal distribution with a little more then 68% of the samples being within one SD of the average. To me they all look possibly the same and the product of random chance. Did you ever just leave the tuner at the best setting and shoot another 18 three shots groups and see if the average changed?

I have certainly shot additional groups with the tuner set at "18", possibly even on the same day, but I would have to dig out my data book to be certain. I also repeated a subset of that specific tuner test (i.e. tuner settings ~12 through 22 using single increments) on two additional occasions and got the exact same results with respect to a nice wide window of minimal group spread between ~14 to 20. I later used that particular rifle/ammunition/"18" tuner setting combination in several F-Class matches with excellent results. Together, those observations lead me to believe the tighter groups in the "window" were not simply statistical variation, but I cannot substantiate that statistically.

In general, I'm not such a strong believer that what we do in the load development process should necessarily exhibit all the properties of a normal distribution, largely because pretty much everything we do in the reloading process is heavily biased toward minimizing group size. Nonetheless, you could be right. I have been trying to avoid tuner discussions for a variety of reasons, and I wish I had avoided allowing myself to be drawn into this one. I think it's probably best if I just bow out now, and leave the discussion to those with vastly more knowledge and experience on the topic. Carry on!

 

[SG4247]

I can say I learned more from this thread in two days, than I did in the two months prior to buying the tuner.

I appreciate all the responses and plan to perform the tuner test again in .001” increments, along with some more load work.

 

[Ccrider]

Make sure to show us your groups with the rifle in tune at your initial tuner setting. Then we will know your rifle’s potential. Do your load work first.

Don’t expect a tuner to make a rifle shooting .25” shoot better. You should initially tune the rifle to shoot its best, and then use the tuner to keep it in tune.

 

[gunsandgunsmithing]

Make sure to show us your groups with the rifle in tune at your initial tuner setting. Then we will know your rifle’s potential. Do your load work first.

Don’t expect a tuner to make a rifle shooting .25” shoot better. You should initially tune the rifle to shoot its best, and then use the tuner to keep it in tune.

Mostly yes, but I wouldn't limit myself to .250 groups if the gun a and load want to do more...but I think we're mostly in agreement. Not many sub .2 guns out there, in any discipline, really.

 

[jackieschmidt]

Not many sub .2 guns out there, in any discipline, really.

^^^^^^^^

 

[JEFFPPC]

Make sure to show us your groups with the rifle in tune at your initial tuner setting. Then we will know your rifle’s potential. Do your load work first.

Don’t expect a tuner to make a rifle shooting .25” shoot better. You should initially tune the rifle to shoot its best, and then use the tuner to keep it in tune.

Your 100 percent correct but the truth of the matter is many if not most want the tuner to turn their rifle into sub .2. Those unwilling to do the work and test on their own will seldom ever get there. Why are some always up "There" and many seldom get a wiff.