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Rifles, Reloading, Optics, Equipment
Reloading
How far apart are "nodes"
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<blockquote data-quote="benchracer" data-source="post: 990227" data-attributes="member: 22069"><p>First, you seem to have an incomplete understanding of what OBT does or how it works. I strongly recommend that you read the info I posted, along with Dan Newberry's explanation of OCW. Even if you do not agree with the conclusions in either source, you will still benefit from understanding the concepts and how they apply relative to this discussion.</p><p> </p><p> </p><p> </p><p>As I mentioned in a previous post, OBT does not predict an accurate seating depth. Though seating depth can have a dramatic effect on overall group size, it has a very small effect on barrel time and a consequently small effect on the velocity range of a given node.</p><p> </p><p>I ran the data you provided through QL, using an OAL of 2.260 and a Sierra 50 grain SP, which is a FB bullet. Knowing your actual base-to-tip length and the actual bullet used could provide more refined results, but the data should get us in the ballpark.</p><p> </p><p>The OBT chart predicts nodes at .900 ms, 1.030 ms, and 1.120 ms. Information in the paper I posted states that a given node typically falls within + or - .020 ms from the OBT value.</p><p> </p><p>Below are the values I used in the prediction, along with the results. There are three distinct nodes in the predicted data. Compare for yourself and let us know, which, if any, node your accuracy load falls into:</p><p> </p><p>[ATTACH]38671[/ATTACH]</p><p></p><p>[ATTACH]38672[/ATTACH]</p></blockquote><p></p>
[QUOTE="benchracer, post: 990227, member: 22069"] First, you seem to have an incomplete understanding of what OBT does or how it works. I strongly recommend that you read the info I posted, along with Dan Newberry's explanation of OCW. Even if you do not agree with the conclusions in either source, you will still benefit from understanding the concepts and how they apply relative to this discussion. As I mentioned in a previous post, OBT does not predict an accurate seating depth. Though seating depth can have a dramatic effect on overall group size, it has a very small effect on barrel time and a consequently small effect on the velocity range of a given node. I ran the data you provided through QL, using an OAL of 2.260 and a Sierra 50 grain SP, which is a FB bullet. Knowing your actual base-to-tip length and the actual bullet used could provide more refined results, but the data should get us in the ballpark. The OBT chart predicts nodes at .900 ms, 1.030 ms, and 1.120 ms. Information in the paper I posted states that a given node typically falls within + or - .020 ms from the OBT value. Below are the values I used in the prediction, along with the results. There are three distinct nodes in the predicted data. Compare for yourself and let us know, which, if any, node your accuracy load falls into: [ATTACH]38671.vB[/ATTACH] [ATTACH]38672.vB[/ATTACH] [/QUOTE]
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Rifles, Reloading, Optics, Equipment
Reloading
How far apart are "nodes"
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