Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Why I think the Satterlee and Audette Ladder Tests Work and Why-- You Decide!
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Veteran" data-source="post: 2435741" data-attributes="member: 118038"><p>One other thought as the barrel harmonics cause sound and pressure waves to move back and forth in the barrel, the amount of friction the bullet experiences going down the barrel is also not a constant as charge weight is increased. So, small changes in bullet contact with the lands and rifling going down the barrel as it twists and turns due to harmonics may also be contributing factor to these flat spots in the velocity curve. A little more friction due to bullet resistance against an undulating barrel that is not perfectly straight for some milliseconds means less velocity at exit. All of these things play into counter intuitive physics results in the real world.</p><p></p><p>Here is an excellent source published in 1997 that essentially analyzes the Audette Ladder Test and says it works for the same reasons I explained above. </p><p> </p><p> Man its all physics!</p><p> </p><p> </p><p> <a href="https://2poqx8tjzgi65olp24je4x4n-wpengine.netdna-ssl.com/wp-content/uploads/2012/07/incremental-load-development-method.pdf" target="_blank"> https://2poqx8tjzgi65olp24je4x4n-wpengine.netdna-ssl.com/wp-content/uploads/2012/07/incremental-load-development-method.pdf </a></p><p> </p><p>By the way, I believe the whole reason you will find a low node, and a high node or several nodes that work where the graph goes up and then flattens again is related to barrel harmonics and sin waves of pressure and sound in the steel barrel. </p><p> </p><p> Different combinations of harmonics are produced with different charge weights, bullet seating, etc. So, you may find a higher velocity node where it all flattens or goes down because the harmonics happened to come back into play again just right.</p><p> </p><p> So as in electrical harmonics, you may get a 2nd, 3rd, or 4th order harmonic sin wave at some different frequency as you go up the velocity curve and find another node. I believe its all related to unique system harmonics in your specific rifle with its specific barrel </p><p> taper and length, and weight, the powder burn rate, the volume of the cartridge, the bullet seating used, the weight of the bullet, </p><p> etc. Then its all vibration of that barrel as the sound and pressure waves move back and forth before the bullet exits.</p><p> </p><p> Explanation of harmonics and orders of harmonics -- ie, sin waves</p><p> </p><p> </p><p> <a href="https://www.electronics-tutorials.ws/accircuits/harmonics.html" target="_blank"> https://www.electronics-tutorials.ws/accircuits/harmonics.html </a></p><p></p><p></p><p>Now, I don't have scientific proof from a lab to prove what I think......Lots of this is my own rationalization of what I see in the data and the graphs in searching for the answer why???? You might say it is a very good hypothesis. I would say yes, I agree, but to prove all this in exacting pinpoint precision will take a major army DOD lab or a major gun or ammo manufacturer to set up a test rig in a lab capable of measuring and logging pressure data at many points along a rifle barrel, shooting actual ammo with differing charge weights, and analyzing the barrel harmonics of that rig in milliseconds of time as each shot is made and chronographed. It could be done, but not by me or you. But, its the only explanation I think matches why this occurs and occurs </p><p>at intervals along the curve with lower, and higher nodes. Now, if anyone else has a better explanation, man I want to hear it.</p><p></p><p>Remember, don't give me any BS about monte carlo runs and statistics. The lab could also run this experiment a statistically valid </p><p>number of times to get a 95% confidence level and I believe they would still see it on the graphs. Its real. I fire at least 4-5 rounds per charge weight when I do it, just to make sure I get better repeatable results.</p></blockquote><p></p>
[QUOTE="Veteran, post: 2435741, member: 118038"] One other thought as the barrel harmonics cause sound and pressure waves to move back and forth in the barrel, the amount of friction the bullet experiences going down the barrel is also not a constant as charge weight is increased. So, small changes in bullet contact with the lands and rifling going down the barrel as it twists and turns due to harmonics may also be contributing factor to these flat spots in the velocity curve. A little more friction due to bullet resistance against an undulating barrel that is not perfectly straight for some milliseconds means less velocity at exit. All of these things play into counter intuitive physics results in the real world. Here is an excellent source published in 1997 that essentially analyzes the Audette Ladder Test and says it works for the same reasons I explained above. Man its all physics! [URL='https://2poqx8tjzgi65olp24je4x4n-wpengine.netdna-ssl.com/wp-content/uploads/2012/07/incremental-load-development-method.pdf'] https://2poqx8tjzgi65olp24je4x4n-wpengine.netdna-ssl.com/wp-content/uploads/2012/07/incremental-load-development-method.pdf [/URL] By the way, I believe the whole reason you will find a low node, and a high node or several nodes that work where the graph goes up and then flattens again is related to barrel harmonics and sin waves of pressure and sound in the steel barrel. Different combinations of harmonics are produced with different charge weights, bullet seating, etc. So, you may find a higher velocity node where it all flattens or goes down because the harmonics happened to come back into play again just right. So as in electrical harmonics, you may get a 2nd, 3rd, or 4th order harmonic sin wave at some different frequency as you go up the velocity curve and find another node. I believe its all related to unique system harmonics in your specific rifle with its specific barrel taper and length, and weight, the powder burn rate, the volume of the cartridge, the bullet seating used, the weight of the bullet, etc. Then its all vibration of that barrel as the sound and pressure waves move back and forth before the bullet exits. Explanation of harmonics and orders of harmonics -- ie, sin waves [URL='https://www.electronics-tutorials.ws/accircuits/harmonics.html'] https://www.electronics-tutorials.ws/accircuits/harmonics.html [/URL] Now, I don't have scientific proof from a lab to prove what I think......Lots of this is my own rationalization of what I see in the data and the graphs in searching for the answer why???? You might say it is a very good hypothesis. I would say yes, I agree, but to prove all this in exacting pinpoint precision will take a major army DOD lab or a major gun or ammo manufacturer to set up a test rig in a lab capable of measuring and logging pressure data at many points along a rifle barrel, shooting actual ammo with differing charge weights, and analyzing the barrel harmonics of that rig in milliseconds of time as each shot is made and chronographed. It could be done, but not by me or you. But, its the only explanation I think matches why this occurs and occurs at intervals along the curve with lower, and higher nodes. Now, if anyone else has a better explanation, man I want to hear it. Remember, don't give me any BS about monte carlo runs and statistics. The lab could also run this experiment a statistically valid number of times to get a 95% confidence level and I believe they would still see it on the graphs. Its real. I fire at least 4-5 rounds per charge weight when I do it, just to make sure I get better repeatable results. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Why I think the Satterlee and Audette Ladder Tests Work and Why-- You Decide!
Top