What should a tuner be expected to do?

That is a crazy amount of data collection but I am very happy to see that these results mimic what I have seen for many years and thousands of shots downrange...

Do not lean on ES/SD to tell you anything worthwhile. Plot every shot and it will tell you all that you need to know.

There is no reliable, repeatable connection between velocity and POI.... there is also little correlation between tight SD/ES and group size. I am sure EVERYONE can toss up a target to show that the numbers agree... and just as easily, others will show that it doesn't.

THUS... IT DOESN'T. A rule that has exceptions is not a rule at all.

I saw this years back when I started being competitive in F class and have seen this time and again over the years from results posted by many other shooters.

Where this FACT started I have no idea but it is unreliable and very easily shown to fail... and thus can lead to very bad assumptions about downrange performance... usually painfully realised during a match when numbers/performance don't line up with real world targets downrange.

The best data is ALWAYS collected by testing at the furthest distances possible (yes, there will be wind... learn to read it). The closer to your maximum engagement distance, the better your data

Instead of spending big money on a fancy chronograph... spend that money on a spotting scope, a long range camera system or the best... an E target. Once you correlate EVERY bullet impact vs conditions at distance, you will be able to 'tune' your set up better and understand what works and what doesn't.

Jerry
 
This further convinces me that I'm just going to stick to bar tables(a pool reference for the uninitiated). IE 50 yards

I've taken some time with the recently posted targets and took a stroll through the 100 yard challenge thread. All I have is questions and they would only be all the obvious ones that I'm sure you guys have considered. No suggestions. I will say that you have been shooting some very interesting lots of higher tier ammo.
 
adamg said:
The guy that developed Optimum Barrel Time analysis of rifle barrels disagrees with you. He says that tuners and things attached via threads at the muzzle don't affect the barrel's vibrations.

https://www.youtube.com/watch?v=7mHxLe-7aMQ
Click to expand...

What do tuners affect (according to that guy)? Perhaps you could give a reference as to where in the over one hour video this is discussed or explained.
 
grauhanen said:
What do tuners affect (according to that guy)? Perhaps you could give a reference as to where in the over one hour video this is discussed or explained.
Click to expand...

He gets into his theory on what is happening with barrel vibrations pretty quick in the video, a few minutes in.

Indeed he says the bending wave is not a factor at all in a rifle barrel.

He mentions the impact of hanging a receiver, suppressor, or muzzle brake at ~12m30s.

I extrapolate that if a receiver, muzzle brake and suppressor have no effect, neither would a tuner. Interestingly, Erik fails to recognize the implications of what is being said here vis-a-vi his tuner advocacy.
 
adamg said:
The guy that developed Optimum Barrel Time analysis of rifle barrels disagrees with you. He says that tuners and things attached via threads at the muzzle don't affect the barrel's vibrations.

https://www.youtube.com/watch?v=7mHxLe-7aMQ
Click to expand...

Well he's wrong. Add weight to a guitar string and listen to it's tone change.
Hell, sit on a yard stick with half of it hanging off your bench, and strum it. Then tape a weight to the end.
 
If this doesn't have an affect, why does everyone worry about strapping on a magnetospeed bayonet to a barrel?

wheel weights, 2 hose clamps... really simple test to prove or not, adding weight to a muzzle can have an affect.... any affect

Jerry
 
adamg said:
The guy that developed Optimum Barrel Time analysis of rifle barrels disagrees with you. He says that tuners and things attached via threads at the muzzle don't affect the barrel's vibrations.

https://www.youtube.com/watch?v=7mHxLe-7aMQ
Click to expand...

Lol, go back and watch it again. Right around the 19 min mark he talks about the correlation of a tuner and the barrel whip, which he calls "bending modes". Talks about how the tuner can bring it all in together, "in line" to get you tight groups. He goes on to saw what he found to be optimal barrel length for the caliber he was using, to "get that tune" without using barrel tuners.
 
wallz said:
Lol, go back and watch it again. Right around the 19 min mark he talks about the correlation of a tuner and the barrel whip, which he calls "bending modes". Talks about how the tuner can bring it all in together, "in line" to get you tight groups. He goes on to saw what he found to be optimal barrel length for the caliber he was using, to "get that tune" without using barrel tuners.
Click to expand...

Thank you.
 
wallz said:
Lol, go back and watch it again. Right around the 19 min mark he talks about the correlation of a tuner and the barrel whip, which he calls "bending modes". Talks about how the tuner can bring it all in together, "in line" to get you tight groups. He goes on to saw what he found to be optimal barrel length for the caliber he was using, to "get that tune" without using barrel tuners.
Click to expand...

Yes, he seems to emphasize that barrel length and diameter are a key in getting the right tune for the centerfire rifles he's discussing. Around 20:21, Long said "I never played with tuners" because he found the right barrel length (and, no doubt, a few other things related to load) to give him his best tune and results.

One of the things Long presented that I found interesting was the theory that bore diameter changed with the "shock wave" that passed back and forth through the barrel after firing. If I understood, he said that if the bullet's exit could be timed so that it when it left the muzzle it would do so with the same bore diameter each time, it would experience consistent gas pressures at the moment it exited. This would contribute importantly to consistency in the flight of the bullet.

Of course, assuming it occurs, the amount of bore diameter change resulting from the passing shockwave must be extraordinarily difficult to measure, if such measurement are at all possible. As presented by Long, perhaps it's still a theory waiting to be tested and proven.
 
Yea, I found the video very interesting in the points that he makes on the instant pressure build up in the chamber and what it does to the barrel.

Interesting thought as well on the "pressure wave" travelling down the barrel and back again, after hitting the end of the barrel. Makes you wonder how long that actually happens; to travel the barrel and back, while you are then sending another round down the barrel.

Knowing that a pressure spike is there, and finding a way to measure it in the barrel as a diameter change would be a very interesting proposition.
 
Not really related to the current discussion but here is my target from today tuning my rifle. The gun is an Anschutz 2007/2013 in a BR stock with a Lowey tuner, 36X Leupold, and shooting Tenex. It’s clear to see that the tuner has an effect on group size. (The pics of the rifle are from a previous range session hence the Midas+ ammo)

hnjVqu4.jpg

O3UhNVG.jpg

hb66ur4.jpg
 
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Underthegun said:
Not really related to the current discussion but here is my target from today tuning my rifle. The gun is an Anschutz 2007/2013 in a BR stock with a Lowey tuner, 36X Leupold, and shooting Tenex. It’s clear to see that the tuner has an effect on group size. (The pics of the rifle are from a previous range session hence the Midas+ ammo)

hnjVqu4.jpg
Click to expand...

A serious question because the answer may not seem obvious. Which tuner setting is the best? (And repeatable?) Is it 250, 300, 350, 450, 475, or 500?

Does this lot of Tenex show group size variation when it's shot without a tuner? How much?
 
grauhanen said:
A serious question because the answer may not seem obvious. Which tuner setting is the best? (And repeatable?) Is it 250, 300, 350, 450, 475, or 500?

Does this lot of Tenex show group size variation when it's shot without a tuner? How much?
Click to expand...

I settled on 475 when I posted that. But since then I’m going to test setting 400 again as it is right in the middle and that whole row averaged under .250”. Setting 475 was repeatable, but I’m thinking that if 400 shoots good, it might give me a bigger window in the tune. I never shot this lot without the tuner as I’ve only got about 2 bricks, so my plan was just to test it with the tuner and find a setting. I’ve got a couple other various lots of Match and one other lot of Tenex, I’m just playing around with those various lots for now, and once they are gone, I’m going to get serious and really lot test with some Match and Tenex.
 
Ok, so I went right out to the range after my last post and tried setting 475 and 400. I think I’m going to settle on 400 as it seems to have the least amount of POI shift, and it averaged slightly smaller, though I don’t think it’s enough to matter overall. I think it’s clear though, that this is not the best lot of ammo for this rifle. I could play around more with other tuner settings, but with the limited amount of that lot I have, I’ll settle for this setting.

p.s. I updated the picture of the rifle to my current bench setup.
JaYOczA.jpg

pkChR7D.jpg
 
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grauhanen said:
A serious question because the answer may not seem obvious. Which tuner setting is the best? (And repeatable?) Is it 250, 300, 350, 450, 475, or 500?

Does this lot of Tenex show group size variation when it's shot without a tuner? How much?
Click to expand...

I had the same question about non tuner groups. Those results look typical of the Eley Match that I shoot. No apparent rhyme or reason to the occasional high or low impact. I am constantly seeing my 10 shot groups “spoiled” by a couple that go high or low. I have started ignoring those for the purposes of data collection. I did nothing different to put them there, so no sense I trying to fix a non-mistake. Hell, at 400yds my groups have several impacts within 4” of the bull. Shoot 20-30 per group at 200+, and the core impacts look great, with Rimfire reality spread up and down based on who knows what. Centerfire I can do 1/2MOA@400, so not my mistakes.
 
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So today, I figured I would try playing with my tuner. I mainly have it for rifle balance, but if I can get it to improve group sizes, why not.
Rifle is a CZ 457 MTR, XRS Stock, Athlon Ares ETR 4.5-30x56, Yodave trigger spring, and a Red Knobb Tuna Can. The weather was a sunny 23c, with a slightly gusty 15km wind from the left.
Ammo was SK Long Range Match. This lot wasn't exactly shooting lights out for me, so I didn't mind shooting a whole bunch of it just to crunch some numbers.
Not the most scientific testing, as I probably should have fired more groups for the other tuner settings for a better comparison. But the results are enough to pique my interest, and for me to share and see what others think.

I started by shooting 20 rounds to sight in, foul, and warm everything up. Then I shot ten groups of ten shots each, one for each tuner setting.
Then I shot another 10 groups, of five rounds each. (Top row is all the first groups)(Bolded numbers are the setting averages)
Groups (2).jpeg

I then selected four promising tuner settings 1,6,8, and 10. I shot two groups of five for each setting, before changing to the next setting. Then I shot one group for each setting for a total of three groups for each setting.
After these groups, 6 and 10 looked promising so I shot another 5 round group at each setting.

Here are the Excel crunched numbers. Average and then Standard Deviation below. The 10 round groups were not used for calculations.
Average and std dev.jpeg
First column is the group average across all settings (The numbers below is the same thing, but using the group averages for 1,6,8 and 10)
Second column is group average across all groups fired.
Third column is group average across all favorable tuner settings. (1,6,8, and 10) And then group average across all other tuner settings. (If you throw out setting 4, the average of all the other tuner settings becomes 0.53, which is almost the exact same as the favourable ones)
Fourth column is group average across the two best tuner settings.

Targets have the tuner setting written on them. All group sizes are from the caliper zeroed at 0.000, so before 0.22 is subtracted.
IMG_6752.jpgIMG_6751.jpg
 

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