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Avoid this pitfall with distance/target based ladder test
- Thread starter Feniks Technologies
- Start date
You have already seen the graphs I posted , I can only assume you dont understand what they really mean , That is my fault for not relaying the info to help you understand. When you have a slower bullet hitting .700 higher than a faster bullet at 100 yards they will hit level at 1000 yds . that is why we use graphs to see barrel movement rate of upswing ,etc.
With the same vertical aim point this graph represents angular changes in the barrel as well as rates of change which helps calculate the lateral velocity of the muzzle at the bullets exit . This means the later they exit the higher the barrel is, so it is moving upward. The slowest round really drops out. this is the proverbial cliff when the muzzle drastically turns downward and travels down at a super fast rate so fast that a bullet drops 3 to 4 inches in only 36 fps change in velocity . And might add that a bullet traveling around 200fps slower hits 1.5 inches higher before the drop off. The trend line always shows up when the conditions allow for a good graph.
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Tokay was speaking tongue in cheek there making fun of the dummymark007
It only means the potential is there with no wind push. Reduced vertical dispersion at longer ranges does not mean the groups will be smaller because slower bullets will drift downwind more. it just means there is less vertical dispersion .The main factor is at what distance do they converge , this is the focal point of tune and the most likely the area in which groups are the tightest if velocities are not level at that moment . I would be glad to show you how to find a natural frequency node if you like , all you need is a old barrel and a chunk of wood. A node is just a intersection of frequencies and has the least lateral movement, in which you will actually feel if you try it . The spot in which is not damped by your finger is the node . This is the spot that has the highest angular movement but 0 lateral movement .
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A vibration/ harmonics implies movement in all directions but barrel harmonics is such a generic term ,the barrel is simply bending straight up and down under recoil because the stock which is heaver is bolted to the bottom and scope is bolted to the top usually about half the weight of the stock, that creates a vertical offset which make the barrel bow up in the middle and bend straight up and down at the muzzle . A tuner just speeds and slows vertical bending. Would you consider a whip as a vibration ? or harmonics? I ask this question a lot so just asking for an opinion .
Ah, I don't see it as "whip" particularly with the heavy barrels many of us use. And IMO the principal phenomenon is indeed vibration from the shot (gas pressure, bullet accelerating down the tube engraving the lands, etc) and it is a set of related vibrations...hence 'harmonics'.
I too am more than willing to be schooled on this, but I still see no reason for such vibrations to sum into pure vertical only movement.
I agree and thought that all of these modes of vibrations are involved, they have to be , but when I started testing with a two differing powder charges I could see they were always hitting straight up and down in the tunnel but outside was a bit obscured at times , but back in the tunnel they always hit straight up and down at least within a half of a bullet ,adjusting the tuner brought them together vertically. slowly through testing we were able identify the majority of the effecting vibrations, and the non effecting which are after the bullet left the barrel. These are under highly controlled conditions, but it becomes more obvious over the years of what is effecting what .
Again, this means the launch angle is different and can be measured.
That slower bullet must physically exit the barrel at a higher point. That point can be calculated and measured without graphs.
Graphs and ladder tests are used when one doesn’t have the tools required to measure. Which is completely understandable as they may be fairly expensive and/or require fairly advanced training to use.
My question is, why hasn’t anyone with the proper tools measured this or why hasn’t someone contracted a company with the proper tools?
It’s literally as easy as:
Slower bullet hit here
Faster bullet hit here
Slower bullet at X velocity needs to have Y angle to hit here
Measure Y angle and verify it’s the required angle
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Specifically, when attempts have been made with tools that can measure things more than ladder tests and bullet holes…..
Such as doppler, extremely high speed cameras, and even basic indicators……the explanations are always very basic and do not support compensation. The only one I can find that used some tools to properly measure is the one @Doom posted. However there’s a handful of differences from centerfire and such in that example. As well as it being a one off test.
The only times compensation is “proven” is when it’s just holes on paper and people need a way to explain why.
As soon as a literal rocket scientist with doppler shows up, the explanations become something completely within the realm of predictable via accepted calculations.
I’m completely open to the idea. If someone can link me to a study or test that involves technology past holes on paper and essentially theories or guessing why the holes went where they did.
But if the argument against doppler radar us “mah paper has bullet holes here” then I’m respectfully not interested in that conversation as it’s gone as far as it can go.
Such as doppler, extremely high speed cameras, and even basic indicators……the explanations are always very basic and do not support compensation. The only one I can find that used some tools to properly measure is the one @Doom posted. However there’s a handful of differences from centerfire and such in that example. As well as it being a one off test.
The only times compensation is “proven” is when it’s just holes on paper and people need a way to explain why.
As soon as a literal rocket scientist with doppler shows up, the explanations become something completely within the realm of predictable via accepted calculations.
I’m completely open to the idea. If someone can link me to a study or test that involves technology past holes on paper and essentially theories or guessing why the holes went where they did.
But if the argument against doppler radar us “mah paper has bullet holes here” then I’m respectfully not interested in that conversation as it’s gone as far as it can go.
and at the end, who would you listen to?
bryan, whos job is to monitoring bullets at every yard of the flight, or random looser on this forum who claim that knows everything about barrel harmonics because he shoots for 40 years?
I was going to stay out of this, but I am positive that claim was never made, theoretically by past results it would seem impossible. Group size in 600 yrd BR have always been roughly half that at 1K.
Litz was at the top of the 1K benchrest world around 7 yrs ago, give or take, long before his AB wez program surfaced, one should ask of him if he tuned his load at that distance, or relied on chrono numbers.
I thought I read the other day where you posted that a 5 or 10 fps increase or decrease at 1K was equivalent to 5" of vertical dispersion. There is not a ballistic app made that would substantiate the claim. If we actually take a ruler to things, 1/2 moa at 1K is around 5", 1/10 of a mil at 1K is 3.6", takes a fair amount of velocity spreads to get an app to change, yet we read claims that + or - is responsible for variations.
IMO, just as no one can actually prove positive compensation at the moment according to some people, I doubt any shooter could shoot at 1K with a chrono and call his shots based off numbers alone. If you continuously have 10" of vertical at 1K, your load is probably not that good or up to competitive BR standards, we all strive for diff levels here.
Maybe I am old, maybe I don't want to play, but if you look at the voices behind almost all theories, or trends to swing the industry to one way of thinking, there is money to be made.
takes a fair amount of velocity spreads to get an app to change, yet we read claims that + or - is responsible for variations....
just for validity, if we dont have access to the algorithm in the ballistic app we dont know how finite/ resolution of the output is
the math may give a answer that is below a rounding threshold etc
but we do know that a slower bullet should land below a faster bullet at same launch angle, there is no debate on that premise
Litz would make far more money if he could publish data that proves positive compensation.
AB sells information.
Right, but is there a formula other than claims as to what a negative 10fps does to bullets, or positive 10fps for that matter? Bullet weight, BC, etc.. all have to play here.
Also, a world class SD is 5 or below.
99.7% of shots with the following SD’s will fall inside the following ES:
5sd = 30es
4sd = 24es
3sd = 18es
2sd = 12es
1sd = 6es
Let’s look at a .284 Shehane running 180 Bergers @ 2900 and 1k.
2870: 262”
2930: 249”
13”
2888: 258”
2912: 253”
5”
2891: 257”
2909: 254”
3”
I won’t go any further as 3sd is likely the absolute top end ammo.
Now, the question is:
How many guys shoot high scores and X counts are doing it with more than a 5sd/30es?
I was not singling Litz out here, as far as I'm concerned, we would not be here w/o him, it was a pretty broad-spectrum statement.
Most of these guys are also sorting and uniforming bullets. So in theory, the BC *should* be very consistent.
Ya. I was just using him as an example.
Quite a few others have accused him of making claims because money. Just happened to use your quote.
sorry not following your question/ answer
all things remaining equal:
10 FPS = 3" or so @ 1000 yards with a 180 berger
if one is not controlling the variables that can be controlled their data is sub standard and possibly irrelevant, and should be treated as such
Also, keep in mind how standard deviation works:
1sd = 68%
2sd = 95%
3sd = 99.7%
So, with a 5sd
Roughly 70% of your shots will have an ES of 10
95% will have an ES of 20
That’s a pretty huge amount of the time.
1sd = 68%
2sd = 95%
3sd = 99.7%
So, with a 5sd
Roughly 70% of your shots will have an ES of 10
95% will have an ES of 20
That’s a pretty huge amount of the time.
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From Cal Zant's Precision Rifle Blog (and this is one quantitatively rigorous dude):
"Remember what expert ballistician and long-range expert Bryan Litz said about ammo with an SD around 10 fps: “Exceptional factory ammunition … Acceptable for many long range shooting applications. 10 fps SD will give you approximately 1 MOA of vertical dispersion at 1000 yards.” I agree with Bryan."
And of course that is 10" vertical dispersion at 1k yards.Just quoting some sources, I have no first hand info to validate this but I do think both Litz and Cal Zant are very believable fellas on these subjects.
Ya. 10sd.
But not just a 10fps difference between shots.
Regardless, most shooters don’t understand the 68/95/99 distribution on standard deviation. And as a result don’t understand you can shoot ver good groups at distance with a high SD and very bad groups with a low SD.
And neither is rare.
That’s how distribution and dispersion works.
What is actually very rare is people mapping each shot with a chrono as well as something like an oehler 89 mapping BC on every shot.
Most all of the claims of bad/good group not matching up with velocity are just normal distribution/dispersion. And the claims lose ground as soon as more measurements are taken.
Otherwise, we wouldn’t constantly have this debate because the evidence against normal distribution would be overwhelming.
Well that explains why my calculated vertical never matches anyone else and between my different programs. I saw it as not linear and was trying to find out specifically why . Thank you for that info .
Not arguing against using the right equipment, The reason no one has done it by the info I have gleaned over the years is that there is no known way to measure the slight angle changes with any of the equipment that has been available to be related to the target. I have been trying to find just that for years .Dr Kolbe came close but it is hard not to change the barrels reaction by putting sensors on it , even a light weight polarizing sheet will change the movement . If military labs could not do it I doubt any civilian would have a better chance but if you know of a way to measure a .001 angular change I would certainly be willing to try it . Possibly there is something now that could measure it accurately but I have seen barrel angle sensors for tanks just sure sure if the resolution would be enough for small arms.
This is something I thought about and have wondered why laser(s) and optics equipment haven't been used as it can measure very very small angular displacements. If equipment can be set up to measure gravity waves, I'd think measuring barrel angles would be a walk in the park . . . ???
The amount angle change that would be required to make positive compensation valuable is absolutely measurable.
You can’t have it both ways.
Either the compensation is negligible if you have a sub 20-30es….. and doesn’t matter anyway.
Or
Compensation can accommodate for larger variances in muzzle velocity in which the amount of angle difference needed is absolutely measurable.
As mentioned above, a 24es with the most common .284 projectile in 1k F open is 5” vertical. And 68% of the shots would be an 8es, 95% of the shots would be 16es.
You’re gonna be hard pressed to get any better than that with compensation.
So, positive compensation would only be useful for fairly large velocity spreads. And if that’s possible, the launch angle is no longer so small you can’t test it with common equipment.
So, guys have to pick one. Are we attempting to positively compensate something that’s damn near impossible to improve up?
Or
Can we compensate for larger velocity spreads in which the launch angle is now enough to measure?
This is yet another “paradox” that comes when you did further into the problem other than “my target has holes here and here. I think it is because of this.”
You can’t have it both ways.
Either the compensation is negligible if you have a sub 20-30es….. and doesn’t matter anyway.
Or
Compensation can accommodate for larger variances in muzzle velocity in which the amount of angle difference needed is absolutely measurable.
As mentioned above, a 24es with the most common .284 projectile in 1k F open is 5” vertical. And 68% of the shots would be an 8es, 95% of the shots would be 16es.
You’re gonna be hard pressed to get any better than that with compensation.
So, positive compensation would only be useful for fairly large velocity spreads. And if that’s possible, the launch angle is no longer so small you can’t test it with common equipment.
So, guys have to pick one. Are we attempting to positively compensate something that’s damn near impossible to improve up?
Or
Can we compensate for larger velocity spreads in which the launch angle is now enough to measure?
This is yet another “paradox” that comes when you did further into the problem other than “my target has holes here and here. I think it is because of this.”
I believe someone said if you have the slower rounds hitting .7” higher @ 100yds, they converge @ 1000.
That’s absolutely not such a small angle change that it can’t be measured.
That’s absolutely not such a small angle change that it can’t be measured.
I think so but bear in mind during recoil while measuring the bending the barrel is moving rearward and nothing can be attached to the barrel so you would have to be able to detect and separate the individual movements as they are happening at the same time .
If a bullet is compensated say 100% at 1000 yards with 36 fps then it will be compensated 100% with 5 fps but you would never see that or be able to quantify that but it is there. Compensation does not work part time , It is always working regardless of the spreads. it just takes larger spreads to see and set up the rates. The bending is in the tenths of a second of angle which is tough to measure with anything and add the rearward barrel movement and a bullet exit trigger on top of that makes it even tougher.
You’re misreading completely.
No one said anything about part time.
I said, either it’s enough to measure or it’s not.
And if it’s too small to measure, then it’s negligible.
I’m pointing out how saying it’s too small to measure contradicts the entire principle.
At some point, the angle is no longer tenths if a second. As that’s not enough to compensate enough to make it usable.
So, it’s either usable and therefore measurable, or it’s not measurable and therefore to small for a human to exploit.
And yes, if it’s tenths of a second of angle, it would show up linearly at ELR ranges.
However, proponents suggest it’s exploitable at 1,000yds and in.
Which no longer limits it to unmeasurable amounts.
Then the argument becomes that a human, with breathing, a heart rate, and another 25 things…..is able to exploit an angle too small to measure.
Doesn’t hold water. Can’t have it both ways.
However, proponents suggest it’s exploitable at 1,000yds and in.
Which no longer limits it to unmeasurable amounts.
Then the argument becomes that a human, with breathing, a heart rate, and another 25 things…..is able to exploit an angle too small to measure.
Doesn’t hold water. Can’t have it both ways.
Also, I’m going to make another point…….
Several in this thread are basically asserting that in their spare time, while shooting outside, at steel or paper, with extremely unsophisticated equipment….
Have been able to show and prove what a guy with the following credentials can’t figure out:
-Rocket Scientist by education and trade
-Air to air missile design
-Chief Ballistician at Berger
-Owns/runs/designed the leading ballistic software in the US (possibly the world)
-That same company’s only purpose is to test things. Every single day. There are employees doing nothing but figuring this stuff out
-Owns equipment light years ahead of what most anyone here has
Again, you’re postulating that part time, non trained, non educated, basically hobbyists in comparison…..
Are able to understand a prove what he and his company cannot??
I’ll free admit it’s possible. But highly unlikely would be an understatement.
If someone walked into your place of employment and told you they know more about your job, that you do full time, and they do on the weekends for fun…..
You’d laugh them out the door.
So, keep some perspective on what some people in this thread are asserting.
Several in this thread are basically asserting that in their spare time, while shooting outside, at steel or paper, with extremely unsophisticated equipment….
Have been able to show and prove what a guy with the following credentials can’t figure out:
-Rocket Scientist by education and trade
-Air to air missile design
-Chief Ballistician at Berger
-Owns/runs/designed the leading ballistic software in the US (possibly the world)
-That same company’s only purpose is to test things. Every single day. There are employees doing nothing but figuring this stuff out
-Owns equipment light years ahead of what most anyone here has
Again, you’re postulating that part time, non trained, non educated, basically hobbyists in comparison…..
Are able to understand a prove what he and his company cannot??
I’ll free admit it’s possible. But highly unlikely would be an understatement.
If someone walked into your place of employment and told you they know more about your job, that you do full time, and they do on the weekends for fun…..
You’d laugh them out the door.
So, keep some perspective on what some people in this thread are asserting.
because that costs money and needs a ROI
if its a small sum then people will play, if its 50k and they will hopefully get 5k in return...your only spending it to tell the internet your correct etc
the answers are either:
yes, im tight
no, im wrong
something is happening but im not sure why, which is most likely the answer
all of those arent worth a penny
the return comes from exploiting that data into a product, seminal, publication
...so you write a 5 page article, and some guy in england makes a product to do "X" and makes a few bucks
my gut says the components/gear/technology are just not good enough at this time so everything is "in the noise" after enough shots down range
Personally I prefer the ARS load development method.
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