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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Berger Bullets Announces Launch of a New Ammo Company
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<blockquote data-quote="Michael Courtney" data-source="post: 983579" data-attributes="member: 28191"><p>We have begun work with the 230 grain bullets, but we are not allowed to release results until they have been approved for public release. There is a process of peer review and review to confirm no confidential information is being released.</p><p></p><p> </p><p></p><p>The chronographs are checked both before leaving the lab and also calibrated in the field immediately before use to an accuracy of 0.1%. 0.1% errors in the velocity measurements might yield errors of 0.5 to 1% in the BC determinations. Most bullets have larger shot to shot variations in BC.</p><p></p><p></p><p></p><p>As experimental scientists who expect our work to be subject to very thorough peer-review processes prior to publication and whose reputations ride on the accuracy and repeatability of our published work, experimental accuracy is an issue with which we take great care. </p><p></p><p>The Kestrel 4500s we use are calibrated at the factory to NIST traceable standards. They are regularly checked in the lab against quality instruments and against each other, and they are checked against each other in the field. We've been using them for many years and are happy to report that they consistently meet their pressure accuracy spec of typical 0.04 inHg and a max of 0.07 in Hg as well as consistently meeting their temperature and humidity specs. A possible inaccuracy of 2.3 parts per thousand in pressure would translate into a BC inaccuracy of less than 0.3%. A worst case scenario where the temperature, humidity, and pressure are all on the edge of the accuracy spec still translates to a BC inaccuracy of less than 0.5%. Potential errors exist with all equipment, but we've found the Kestrels to be reliable and any errors they might introduce to BC measurements are minimal.</p><p></p><p>The attached picture shows three Kestrels side by side. In a perfect world, they would read exactly the same to all four significant digits. The older unit on the left that has provided many years of service is reading low by 0.04 or 0.05 in Hg. This 0.17% error would yield a BC error that is 0.17% too high.</p><p></p><p>As a final check on system accuracy, we also always measure the BC of a standard bullet which we have found to give the same BC under many different conditions and circumstances over time. Any error with the chronographs, spacing, or environmental measurements would show up in the BC determination of this standard bullet. It never has.</p></blockquote><p></p>
[QUOTE="Michael Courtney, post: 983579, member: 28191"] We have begun work with the 230 grain bullets, but we are not allowed to release results until they have been approved for public release. There is a process of peer review and review to confirm no confidential information is being released. The chronographs are checked both before leaving the lab and also calibrated in the field immediately before use to an accuracy of 0.1%. 0.1% errors in the velocity measurements might yield errors of 0.5 to 1% in the BC determinations. Most bullets have larger shot to shot variations in BC. As experimental scientists who expect our work to be subject to very thorough peer-review processes prior to publication and whose reputations ride on the accuracy and repeatability of our published work, experimental accuracy is an issue with which we take great care. The Kestrel 4500s we use are calibrated at the factory to NIST traceable standards. They are regularly checked in the lab against quality instruments and against each other, and they are checked against each other in the field. We've been using them for many years and are happy to report that they consistently meet their pressure accuracy spec of typical 0.04 inHg and a max of 0.07 in Hg as well as consistently meeting their temperature and humidity specs. A possible inaccuracy of 2.3 parts per thousand in pressure would translate into a BC inaccuracy of less than 0.3%. A worst case scenario where the temperature, humidity, and pressure are all on the edge of the accuracy spec still translates to a BC inaccuracy of less than 0.5%. Potential errors exist with all equipment, but we've found the Kestrels to be reliable and any errors they might introduce to BC measurements are minimal. The attached picture shows three Kestrels side by side. In a perfect world, they would read exactly the same to all four significant digits. The older unit on the left that has provided many years of service is reading low by 0.04 or 0.05 in Hg. This 0.17% error would yield a BC error that is 0.17% too high. As a final check on system accuracy, we also always measure the BC of a standard bullet which we have found to give the same BC under many different conditions and circumstances over time. Any error with the chronographs, spacing, or environmental measurements would show up in the BC determination of this standard bullet. It never has. [/QUOTE]
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Berger Bullets Announces Launch of a New Ammo Company
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