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Rifles, Reloading, Optics, Equipment
Reloading
First Ladder Test - need help
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<blockquote data-quote="Kennibear" data-source="post: 952758" data-attributes="member: 51650"><p>Dr. Vette</p><p></p><p>I see your line of thought. The bullet strikes on target are very random. By isolating one parameter- Vertical Dispersion from velocity variation- as opposed to two parameters, vertical and horizontal, the only three shots clustering on the target are #13, #14 and #15. Since the powder increases cause vertical dispersion because of velocity increases that parameter caught my attention. Of all the other shots- vertically- there are no more than two consecutive that display low (vertical) dispersion. Given that book max is already exceeded by the powder charge of #14, the cautious side of me would approach #14 from the lesser not greater charge.</p><p></p><p>What is missing is the velocity of each shot. If the velocity shows a high delta (change) between #13, #14 and #15 yet low vertical dispersion that is where the node lies. If the velocity delta is low then it is meaningless and indicates that the powder charge has reached diminishing returns of velocity vs. pressure. Since #14 is about book max and the velocity/pressure curve flattens above 65Kpsi (i.e. the velocity remains constant while the pressure increases geometrically) with current powder technology that is possible.</p><p></p><p>All that being said, if you compressed the target horizontally and just look at where the bullets struck vertically, only 13,14 &15 are grouped together. Any other three consecutive shots are random.</p><p></p><p>KB</p></blockquote><p></p>
[QUOTE="Kennibear, post: 952758, member: 51650"] Dr. Vette I see your line of thought. The bullet strikes on target are very random. By isolating one parameter- Vertical Dispersion from velocity variation- as opposed to two parameters, vertical and horizontal, the only three shots clustering on the target are #13, #14 and #15. Since the powder increases cause vertical dispersion because of velocity increases that parameter caught my attention. Of all the other shots- vertically- there are no more than two consecutive that display low (vertical) dispersion. Given that book max is already exceeded by the powder charge of #14, the cautious side of me would approach #14 from the lesser not greater charge. What is missing is the velocity of each shot. If the velocity shows a high delta (change) between #13, #14 and #15 yet low vertical dispersion that is where the node lies. If the velocity delta is low then it is meaningless and indicates that the powder charge has reached diminishing returns of velocity vs. pressure. Since #14 is about book max and the velocity/pressure curve flattens above 65Kpsi (i.e. the velocity remains constant while the pressure increases geometrically) with current powder technology that is possible. All that being said, if you compressed the target horizontally and just look at where the bullets struck vertically, only 13,14 &15 are grouped together. Any other three consecutive shots are random. KB [/QUOTE]
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First Ladder Test - need help
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