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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Does velocity affect ballistic coefficient?
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<blockquote data-quote="Mikecr" data-source="post: 2274121" data-attributes="member: 1521"><p>Why is the bullet still climbing from 415 to 525? Are you adjusting the scope for these different ranges, and the disparity (highness of shots) is w/resp to what should be zero at those ranges? That's likely it, just want to be clear.</p><p></p><p>BC does change with velocity, and with air density, as these affect drag. If you knew what velocity and air density conditions Hammer tested at to determine a BC of .230 it could really help. Your ballistic software could use that info to correct for local situation.</p><p>It's more accurate to determine BC from measured velocity decay over distance (more accurate than drops), but Hammer's numbers might be pretty good. I'm sure they were validated many times by users.</p><p></p><p>With your low ES, and consistent info near muzzle, you could now setup the chrono at 100yds or 200yds and shoot through it. See what velocity is slowing to by that range. Then adjust BC in software to match that velocity decay & see what you get. Always measure & log your air density conditions for this kind of testing. That needs to be used in your software.</p></blockquote><p></p>
[QUOTE="Mikecr, post: 2274121, member: 1521"] Why is the bullet still climbing from 415 to 525? Are you adjusting the scope for these different ranges, and the disparity (highness of shots) is w/resp to what should be zero at those ranges? That's likely it, just want to be clear. BC does change with velocity, and with air density, as these affect drag. If you knew what velocity and air density conditions Hammer tested at to determine a BC of .230 it could really help. Your ballistic software could use that info to correct for local situation. It's more accurate to determine BC from measured velocity decay over distance (more accurate than drops), but Hammer's numbers might be pretty good. I'm sure they were validated many times by users. With your low ES, and consistent info near muzzle, you could now setup the chrono at 100yds or 200yds and shoot through it. See what velocity is slowing to by that range. Then adjust BC in software to match that velocity decay & see what you get. Always measure & log your air density conditions for this kind of testing. That needs to be used in your software. [/QUOTE]
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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Does velocity affect ballistic coefficient?
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