Tuning at 100 yards

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grauhanen

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Recently I was shooting a rifle at 100 yards with three different lots of 2024-manufactured Lapua Midas. With each lot I shot some ten-shot groups without the tuner and some with it at various settings. The tuner is a standard Harrell tuner. The barrel is 26" in length and 0.925" in diameter.

The targets shown below are numbered 1 - 8 and show the lots as A, B, or C. Each of the four bulls eyes is numbered 1 - 4 according to the target number.

The targets indicate only if a tuner was used, not its setting.

What, if anything, can be determined by the results?

Below, Targets 1 - 3 with Midas Lot A.



Below, Targets 4 - 6 with Midas Lot B.



Below Targets 7 - 8 with Midas Lot C

 
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I'm not sure if I am stating the obvious here. but just having a tuner on a barrel means nothing. you have to find that proper setting of the tuner to get the groups shrunk. it may be a case as well that you won't find a proper setting with a particular tuner either. there is definitely some magic to making the tuner work.
 
So without going thru every setting on the tuner. Just slapping a tuner on and shooting a couple random groups on a random setting on the tuner. Sounds like you are trying to prove they dont work and not giving the tuner a proper test.

Wouldn't the proper way is. Figure which 3 lot numbers shoot the best. Then shoot every setting of the tuner with the best lot..
 
There is something to note with Lot B. Four of the six w/tuner targets have an errant round at 8 o'clock. This does not occur on any of the w/o tuner targets for lot B or any of the others for that matter. I believe that it is important to remember that barrel whip is not just in the vertical axis. Numerous times in the past I have seen errant wide impacts occur in the 'out of tune' range of settings.
 
OkayShooter said:
So without going thru every setting on the tuner. Just slapping a tuner on and shooting a couple random groups on a random setting on the tuner. Sounds like you are trying to prove they dont work and not giving the tuner a proper test.
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Your remark is baseless. I have said on many threads in this forum and elsewhere that tuners work. To illustrate my faith in tuners, I can note that during the last sale at Nordic I bought two Starik tuners to add to those I already have. If I didn't believe in them, I wouldn't have them.

I have also said that it isn't necessarily easy to find a setting that actually allows the tuner to do its job. Furthermore, I've said that slapping a tuner on and shooting a couple of random groups proves nothing.
 
Williwaw said:
There is something to note with Lot B. Four of the six w/tuner targets have an errant round at 8 o'clock. This does not occur on any of the w/o tuner targets for lot B or any of the others for that matter. I believe that it is important to remember that barrel whip is not just in the vertical axis. Numerous times in the past I have seen errant wide impacts occur in the 'out of tune' range of settings.
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That's a good observation. Whether or not "barrel whip" or something else is the cause, errant POIs can occur in any direction.
 
This morning I continued testing at 100 yards with the tuner. I used the same rifle and tuner and the same lots of ammo. I was only able to shoot 17 ten shot groups before it warmed up and became too breezy to record worthwhile results.

Again, as previously, I have indicated only whether a tuner was used, not its setting. As with the previous targets, a variety of tuner settings were used.

What, if anything, can be determined by the results?

Below are today's targets 1 - 3 again with Midas Lot A.



Below are Targets 4 - 5.

 
Everyone has an opinion but very few do any testing or show their results. The groups being posted are fine examples of marksmanship. Id be curious to see other targets being posted with comparable results and with the regularity of these results. I find it fascinating and thank everyone who tries things and shares with others the results.
 
grauhanen said:
Your remark is baseless. I have said on many threads in this forum and elsewhere that tuners work. To illustrate my faith in tuners, I can note that during the last sale at Nordic I bought two Starik tuners to add to those I already have. If I didn't believe in them, I wouldn't have them.

I have also said that it isn't necessarily easy to find a setting that actually allows the tuner to do its job. Furthermore, I've said that slapping a tuner on and shooting a couple of random groups proves nothing.
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And that's all I seen in this post. Slapping on a tuner, shooting a random group on a random setting and saying be the judge, or what can the determination be? So inconclusive results and not a fair test of the tuner. I can slap a supercharger on my Corolla, but without doing any tuning I enter down the road for failure.
 
grauhanen said:
That's a good observation. Whether or not "barrel whip" or something else is the cause, errant POIs can occur in any direction.
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You may have put barrel whip in quotes because it is not the most helpful descriptor of the phenomena. More correctly we are dealing with harmonics. For anyone trying to wrap their minds around this go watch some YouTube videos of jet boats on the Columbia river. Barrel harmonics operate much like standing waves in the river. Note that some are very stable and some oscillate in both position and amplitude. There are many waves/tuner settings which will show improvement but some are better than others. They would have optimal slope, less spurious noise, stable amplitude and timing. At this point we encounter the debate of what point of the wave to tune to which is of considerable importance also.

Hope this helps somebody. I know there is somebody out there imagining themselves in the cockpit of their new river boat.
 
Williwaw said:
You may have put barrel whip in quotes because it is not the most helpful descriptor of the phenomena.
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I put the term in quotes because the words were yours.

When referring to "barrel whip" or harmonics some caution should be used.

The term barrel harmonics is often used as a default explanation for ammo behaviour that's difficult to understand. Attributing errant shots to barrel harmonics explains little. It's necessary to say more about why a particular round had a different experience with the barrel than other rounds with similar muzzle velocities.

For example, what causes two or more rounds with very similar MVs to have very dissimilar POIs? Similarly, what causes two or more rounds with very different MVs to have a very alike POI? Explaining everything such as these by saying it's barrel harmonics sounds good but explains nothing.
 
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Some tentative thoughts about the results. These are not conclusions.

It's difficult to establish a base line, a standard against which to compare results between the bare barrel and the barrel with the tuner. Ammo variation at 100 yards often means considerable variation in group sizes. It would be necessary to shoot a lot more groups with and without the tuner than I was prepared to do or had time and ammo for.

The effects on trajectory of ammo flaws are more pronounced at 100 than they are at 50. What may not be a "flyer" or errant shot at 50 can clearly become one at twice the distance. It's possible that if a good tuner setting was used on some of the groups, ammo defects causing errant POI couldn't be "corrected" or "fixed" by the tuner. This question needs further attention.

It's possible that the barrel was never or insufficiently affected by the tuner, regardless of the setting. The barrel is .925" in diameter and possibly a bit too heavy for a 26" barrel to be tuned by a standard tuner. Perhaps the standard Harrell tuner was insufficiently heavy and needs extra weight. I have weights for it and will revisit this at some time in the future.
 
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