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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Hammer ballistic coefficient tests...
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<blockquote data-quote="entoptics" data-source="post: 2612915" data-attributes="member: 104268"><p>I did intend to show it as a ratio, but very much appreciate your effort to also present it as the relative difference. Either method may be more or less helpful depending on how one prefers to digest the data. Apologies that my language wasn't clear.</p><p></p><p></p><p>The N for the Hammer bullets was between 5 and 9 (first load testing, done only in the last few weeks). </p><p></p><p>For most of the others, N is from 10-80. I have indeed noticed significant variation in measurements from bullet to bullet, and from outing to outing, but it's usually on the order of no more than ± 2% relative (see chart below for examples). I'd consider this "within error" for the LabRadar/Kestrel setup.</p><p></p><p>I've never intentionally tried to measure a range of velocities, but have some data for the same bullet in say a 30-06 and a 300 WM, and haven't noticed a huge difference. That said, I've not "crunched the numbers". I intend to try the remaining 284 Hammers/SBDII in my 7 Rem Mag, so I'll collect some data there and publish it here eventually.</p><p></p><p></p><p>Weather was 74.9° to 61.5°, station pressure from 27.514 - 27.523 inHg, and humidity was 30.2% - 42.85%. Readings were taken every 15 minutes or so, and the nearest time to the shot was used for the B.C. calculator input.</p><p></p><p>In my experience, the calculated B.C. doesn't change much in different weather conditions. After all, that's it's entire purpose. Here's a chart of T vs BC from rifles with enough data over a long period of time to show variation (there isn't much if any).</p><p></p><p>[ATTACH=full]392176[/ATTACH]</p><p></p><p>The title was chosen because that is the new data here for me, and the unusual results for the Hammer bullets are noteworthy. I only showed the other bullets because the Hammer numbers were so startling. I wanted to ensure that readers could see that other bullets came in reasonably close to their manufacturers stated values, to help validate the testing of the Hammers.</p></blockquote><p></p>
[QUOTE="entoptics, post: 2612915, member: 104268"] I did intend to show it as a ratio, but very much appreciate your effort to also present it as the relative difference. Either method may be more or less helpful depending on how one prefers to digest the data. Apologies that my language wasn't clear. The N for the Hammer bullets was between 5 and 9 (first load testing, done only in the last few weeks). For most of the others, N is from 10-80. I have indeed noticed significant variation in measurements from bullet to bullet, and from outing to outing, but it's usually on the order of no more than ± 2% relative (see chart below for examples). I'd consider this "within error" for the LabRadar/Kestrel setup. I've never intentionally tried to measure a range of velocities, but have some data for the same bullet in say a 30-06 and a 300 WM, and haven't noticed a huge difference. That said, I've not "crunched the numbers". I intend to try the remaining 284 Hammers/SBDII in my 7 Rem Mag, so I'll collect some data there and publish it here eventually. Weather was 74.9° to 61.5°, station pressure from 27.514 - 27.523 inHg, and humidity was 30.2% - 42.85%. Readings were taken every 15 minutes or so, and the nearest time to the shot was used for the B.C. calculator input. In my experience, the calculated B.C. doesn't change much in different weather conditions. After all, that's it's entire purpose. Here's a chart of T vs BC from rifles with enough data over a long period of time to show variation (there isn't much if any). [ATTACH type="full"]392176[/ATTACH] The title was chosen because that is the new data here for me, and the unusual results for the Hammer bullets are noteworthy. I only showed the other bullets because the Hammer numbers were so startling. I wanted to ensure that readers could see that other bullets came in reasonably close to their manufacturers stated values, to help validate the testing of the Hammers. [/QUOTE]
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Hammer ballistic coefficient tests...
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