Tuners

[Fast14riot]

Temp and altitude are not the same as station pressure. Bryan covers that testing in his videos, too.

It is smart load development though, I often adjust my loads from winter to summer to stay in my velocity sweet spot. Ammo temps from 40 to 120 are common.

Curious though, what are your targets and metric for "always shoots the same?"

 

[ELR LVR]

Temp and altitude are not the same as station pressure. Bryan covers that testing in his videos, too.

It is smart load development though, I often adjust my loads from winter to summer to stay in my velocity sweet spot. Ammo temps from 40 to 120 are common.

Curious though, what are your targets and metric for "always shoots the same?"

Consistently shoots approx 1/3 MOA at 600
On different days, different temps, Hg is pretty consistent, I'd have to look at my books but if I remember right it's usually around 27.0 Hg
I don't load test during storm fronts so haven't tested in that condition
At that distance, If I am using paper targets, they are 8.5 x 11 binder paper w/ Orange Paster
I have a big enough collection of them that it shows the rifle does the same every outing I took it out on.
Night /Day/ Cold/ Warm.
Although I will say most of the dispersion is vertical. But again I shoot with a bipod and no rear bag.
(what does it matter what the Station Pressure is, if that is the pressure at a given reporting Station),
I use the actual pressure at my physical location)
Readings are taken from a Garmin Rhino 755t
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I should probably add here, our disciplines are likely different
Mine is to be able to go out anytime, preloaded, and shoot animals
(Many counties in Nevada allow Night hunting, with spotlights,
and a Mt. Lion Tag is like 40 bucks, when you cannot even mention that in Ca
Anyway for what I usually do, I dont have the luxury of adjusting loads out in the field for the conditions

 

[Fast14riot]

Station pressure is the pressure at your location. Barometric pressure, often used as a generic term, is relative to sea level and changes with density altitude. Barometric pressure is adjusted for altitude from station pressure.

And you have the data for shot dispersion based on temps and weather, "most the dispersion is vertical" and other more experienced tuner users than me have said tuners tune vertical.

I know you said you ordered a tuner, but sounds to me like you're prime for testing all this out! It would be interesting to see your results compared to your previous data.

 

[ELR LVR]

I am measuring "Absolute" with my GPS....which is technically the same as "Station"
Correct?
Although both different than Barometric

 

[gunsandgunsmithing]

Seating depth works to tune the load, a tuner tunes the shooting system to the conditions. As Bryan points out in this video, barometric pressure seems to be the biggest atmospheric effect on tune. I have noticed it as well, but until recent years I haven't felt I had enough skill to determine it wasn't me causing issues. Which is partly why I have decided on a tuner for my new long range gun. There is a part 2 video with more testing and analysis.

[Youtube]

A caveat on your take from Bryan's videos is that barometric pressure was most critical in HIS TEST. His location during testing saw very little temperature change, so that aspect wasn't really tested. Only barometer. His testing is good but his testing conditions are unlike most of us will see. I find temp AND pressure both important to tune. If I had to pick only one, it'd be temperature, though

 

[gunsandgunsmithing]

I am measuring "Absolute" with my GPS....which is technically the same as "Station"
Correct?
Although both different than Barometric

Not sure what Absolute is but station pressure is the weight of a cubic ft of air, uncorrected for variables like humidity, altitude and temp.

 

[ELR LVR]

Not sure what Absolute is but station pressure is the weight of a cubic ft of air, uncorrected for variables like humidity, altitude and temp.

I learned the term as "Absolute" ....the term Station is unfamiliar to me but am reading they are the same thing.
What I am basically getting at is............
...What is important for me is the actual "Station" or "Absolute" reading of pressure at my specific location at the time of shooting.
Why would I correct for sea level if I am not flying a plane to relate it to ground level? Lol
And due to the fact I change elevations so much this is important when I enter this informtion into my shooting App to provide me a trajectory drop chart.
----------------------------
I once had my load "Dialed" for my 7/08 and really didnt think I changed elevation much one time and my shots were hitting 1 full foot high at 1000 yds, but were consistent
I took a reading and sure enough....it now coincided
I now take a reading every time and log it when I test
It seems to coincide very well with my Lapua App
What I also found VERY important to make your shots coincide throughout the trajectory range is
...Make sure your scope height above bore centerline is measured well and accurately.
Otherwise every adjustment for every distance will be off except for one yardage

 

[gunsandgunsmithing]

I learned the term as "Absolute" ....the term Station is unfamiliar to me but am reading they are the same thing.
What I am basically getting at is............
...What is important for me is the actual "Station" or "Absolute" reading of pressure at my specific location at the time of shooting.
Why would I correct for sea level if I am not flying a plane to relate it to ground level? Lol
And due to the fact I change elevations so much this is important when I enter this informtion into my shooting App to provide me a trajectory drop chart.
----------------------------
I once had my load "Dialed" for my 7/08 and really didnt think I changed elevation much one time and my shots were hitting 1 full foot high at 1000 yds, but were consistent
I took a reading and sure enough....it now coincided
I now take a reading every time and log it when I test
It seems to coincide very well with my Lapua App
What I also found VERY important to make your shots coincide throughout the trajectory range is
...Make sure your scope height above bore centerline is measured well and accurately.
Otherwise every adjustment for every distance will be off except for one yardage

I use station..or Absolute but temp is critical too. Honestly, the group you posted above looks like it's a bit out of tune but it comes down to discipline and what's acceptable. Vertical is the first indicator of tune going away. If a gun always has vertical it can certainly be something else, like handling or setup.

 

[ELR LVR]

I use station..or Absolute but temp is critical too. Honestly, the group you posted above looks like it's a bit out of tune but it comes down to discipline and what's acceptable. Vertical is the first indicator of tune going away. If a gun always has vertical it can certainly be something else, like handling or setup.

I believe you are right, Although each round was progressively heating up in that case of the last group I posted.
Each shot showed to be climbing.
That 3rd highest shot SHOULD have been a slight increase in velocity due to temp
I mainly wanted to just see how wacky things would go if I left a round in the chamber with the bolt closed
(As if waiting for a shot that might happen any second so you dont chance even having the bolt lifted because that split second is too long)
Any other time I would not leave a Round cooking in the hot chamber that amount of time.
I liked the test results at that short range but need to repeat the same again at longer range
--------------
So....... more testing with a Tuner will come this season
I wonder if it will tune out vertical from leaving a round in the chamber?
That would be cool!

 

[gunsandgunsmithing]

I believe you are right, Although each round was progressively heating up in that case of the last group I posted.
Each shot showed to be climbing.
That 3rd highest shot SHOULD have been a slight increase in velocity due to temp
I mainly wanted to just see how wacky things would go if I left a round in the chamber with the bolt closed
(As if waiting for a shot that might happen any second so you dont chance even having the bolt lifted because that split second is too long)
Any other time I would not leave a Round cooking in the hot chamber that amount of time.
I liked the test results at that short range but need to repeat the same again at longer range
--------------
So....... more testing with a Tuner will come this season
I wonder if it will tune out vertical from leaving a round in the chamber?
That would be cool!

I just don't let a round cook for more than a few seconds, typically. Powder being a cellulose product, it's a decent insulator, so doesn't change super fast. I think that's why I don't see tune change so much, if any, due to bbl temp but rather, ambient, as the powder has time to change.

You and others have touched on station pressure as well as temps so I'll add what I've been able to observe a bit.

First thing is, smokeless powder turning from a solid into a gas is a chemical reaction and all chemical reactions are temp dependent.
The other thing is that air pressure very much appears to have an offsetting affect on tune as opposed to temp. Which very well may explain why identical temp changes from day to day...one day the tune clearly goes away but the next, it seems to hold tune very well. Pressure and temp are related but they don't always change linearly and the same from day to day, for example. I've seen this both ways many times but the first was in tornadic conditions where temp was stable but tune left, badly and I struggled to find it moving the tuner the way I "thought" based on temp and group shapes. Something to keep in mind is all. But the key to keeping a gun in tune is generally group shape. I can't emphasize that enough. Shooting in a tornado or a hurricane, where the air pressure just plummets, does seem to change the direction you would need to go, be it tuner, seating or powder, though. I've tested this three times and it seemed to hold true. Tough conditions to replicate, fortunately.

 

[ELR LVR]

I just don't let a round cook for more than a few seconds, typically. Powder being a cellulose product, it's a decent insulator, so doesn't change super fast. I think that's why I don't see tune change so much, if any, due to bbl temp but rather, ambient, as the powder has time to change.

You and others have touched on station pressure as well as temps so I'll add what I've been able to observe a bit.

First thing is, smokeless powder turning from a solid into a gas is a chemical reaction and all chemical reactions are temp dependent.
The other thing is that air pressure very much appears to have an offsetting affect on tune as opposed to temp. Which very well may explain why identical temp changes from day to day...one day the tune clearly goes away but the next, it seems to hold tune very well. Pressure and temp are related but they don't always change linearly and the same from day to day, for example. I've seen this both ways many times but the first was in tornadic conditions where temp was stable but tune left, badly and I struggled to find it moving the tuner the way I "thought" based on temp and group shapes. Something to keep in mind is all. But the key to keeping a gun in tune is generally group shape. I can't emphasize that enough. Shooting in a tornado or a hurricane, where the air pressure just plummets, does seem to change the direction you would need to go, be it tuner, seating or powder, though. I've tested this three times and it seemed to hold true. Tough conditions to replicate, fortunately.

Lol the worst I've ever encountered is shooting in 18 Mph wind.
I had to dial in 2 full Mils for windge and was back on
Calif has it's advantages.
I would not know what to do in pre tornado weather.

 

[Fast14riot]

Storm conditions don't have to be present where you are for the pressure to drop, just in the area. I've shot matches the day before a big storm and the pressure was already falling and continued to do so throughout the day, but was otherwise overcast and pleasant.

Regarding Bryan's testing, yes for his rifle and tune in his location station pressure was the first factor he looked at but also had data on temperature.

Getting the barrel hot like we do in F/class with 20 shot strings, letting a round cook is not a good idea, however one thing some don't test is what happens after you let the barrel cool a few minutes then shoot. Mine will shoot low after sitting for a few minutes then go right back.

 

[Nvcnvc]

95 proof, 80% Rye, 20% Barley, Old Overholt Monongahela Mash.
One hell of a tuner......

Especially when accompanied by an Arturo Fuentes King T! Heaven!

 

[Nvcnvc]

I've yet to see anyone who "debunks" tuners actually test them in the way that people in the know use them, or the way the manufacturer says to use them. They don't believe they work, so they do crap testing to confirm what they want to find. I expect this from Hornady. I'm disappointed that Litz went this route.

If I am not mistaken, Litz said that he could not repeat the results in his setup, not that they would not work for anyone. Anything that changes barrel harmonics will affect bullet flight and impact on target. That’s just basic physics. Finding a repeatable process is the trick. I use them but I am not messing with them during a match.

 

[TC260]

If I am not mistaken, Litz said that he could not repeat the results in his setup, not that they would not work for anyone. Anything that changes barrel harmonics will affect bullet flight and impact on target. That’s just basic physics. Finding a repeatable process is the trick. I use them but I am not messing with them during a match.

I relistened to the Hornady podcast a few days ago and they largely said the same thing....they didn't find anything repeatable but they didn't say they don't work full stop. Really that's all any scientific research can do, report the procedures and results and leave it at that. The goal of science is to objectively measure and quantify things, not to validate our beliefs. Sometimes experiments support our beliefs, sometimes they don’t, that’s just the way the cookie crumbles.

 

[Rob01]

I relistened to the Hornady podcast a few days ago and they largely said the same thing....they didn't find anything repeatable but they didn't say they don't work full stop. Really that's all any scientific research can do, report the procedures and results and leave it at that. The goal of science is to objectively measure and quantify things, not to validate our beliefs. Sometimes experiments support our beliefs, sometimes they don’t, that’s just the way the cookie crumbles.

So you are saying “trust the science”? Lol

 

[gunsandgunsmithing]

I relistened to the Hornady podcast a few days ago and they largely said the same thing....they didn't find anything repeatable but they didn't say they don't work full stop. Really that's all any scientific research can do, report the procedures and results and leave it at that. The goal of science is to objectively measure and quantify things, not to validate our beliefs. Sometimes experiments support our beliefs, sometimes they don’t, that’s just the way the cookie crumbles.

Simply put, they moved their tuner randomly, expecting predictable and repeatable results. I use the word randomly because unless you know an expected result from changing, well, anything...it's just guessing, or random. Knowing how much to move at a time to get predictable results comes from testing that should've been done prior to their published test. It boils down to GIGO.

 

[TC260]

So you are saying “trust the science”? lol

Haha I hear what you’re saying my friend

I don’t mean the politicized version of “science” just the scientific process in general. I read research literature all the time in another field, one group does a study, another builds off that, and another builds off of that and over time conclusions are based on a body of evidence. That’s why I don’t worry about any one study, as the old saying goes, “ time will tell”

 

[Rob01]

I trust my own science and testing. I don’t take someone’s tests that don’t go like they think and then all of a sudden my experience that shows them working is all wrong because of their test. I know what works for me and why I use it.

 

[Bill Norris]

I trust my own science and testing. I don’t take someone’s tests that don’t go like they think and then all of a sudden my experience that shows them working is all wrong because of their test. I know what works for me and why I use it.

Smart man. Time and time again we all find it best to test our own stuff to find out what works best for us. Everyone's rifle, load, tuner, bench manners & conditions will all be different.