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Long Range Hunting & Shooting
BC always better on lead core bullets vs. copper. Why?
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<blockquote data-quote="Jed Eckert" data-source="post: 1717394" data-attributes="member: 111377"><p>Thanks for your time.</p><p>Currently I'm using barnes 150 ttsx out of a .30-06 for blacktail deer and pigs to 500 max. Plan on going to barnes 175 lrx and adding elk in the coming year. For whatever its worth on wikipedia, It looks like Mass is an integral part of the equation, I should have looked it up before I asked.</p><p>Projectile diameter and the shape of the projectile and are also very important.</p><p></p><p>"The formula for calculating the ballistic coefficient for small and large arms projectiles <em>only</em> is as follows:</p><p></p><p><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b109f3d8f77f6ebfe2df5de92e84d5614b7bee8c" alt="" class="fr-fic fr-dii fr-draggable " style="" /> <a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-2" target="_blank">[2]</a></p><p>Where:</p><p></p><ul> <li data-xf-list-type="ul"><em>BCProjectile</em> = ballistic coefficient as used in point mass trajectory from the Siacci method (less than 20 degrees).<a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-3" target="_blank">[3]</a></li> <li data-xf-list-type="ul"><em>m</em> = mass of bullet</li> <li data-xf-list-type="ul"><em>d</em> = measured cross section (diameter) of projectile</li> <li data-xf-list-type="ul"><em>i</em> = Coefficient of form</li> </ul><p>The Coefficient of form (<em>i</em>) can be derived by 6 methods and applied differently depending on the trajectory models used: G Model, Beugless/Coxe; 3 Sky Screen; 4 Sky Screen; Target Zeroing; Doppler radar.<a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-4" target="_blank">[4]</a><a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-Rinker_1999_176-5" target="_blank">[5]</a></p><p></p><p>Here are several methods to compute <em><strong>i</strong></em> or <strong>Cd</strong>:</p><p></p><p><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2df3e7203bb0990c6ffeaad0ddee527b6d8fd6dd" alt="" class="fr-fic fr-dii fr-draggable " style="" /> <a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-Cline_2002_44-6" target="_blank">[6]</a><a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-Rinker_1999_176-5" target="_blank">[5]</a><a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-7" target="_blank">[7]</a></p><p>Where:</p><p></p><ul> <li data-xf-list-type="ul"><em>i</em> = Coefficient of form.</li> <li data-xf-list-type="ul"><em>n</em> = number of calibers of the projectile's <a href="https://en.wikipedia.org/wiki/Ogive" target="_blank">ogive</a>.</li> </ul><p>Where <em>n</em> is unknown:</p><p><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2625845546a7b804c77799f5e40c3dd539fd655d" alt="" class="fr-fic fr-dii fr-draggable " style="" /> <a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-Cline_2002_44-6" target="_blank">[6]</a></p><p>Where:</p><ul> <li data-xf-list-type="ul"><em>n</em> = number of calibers of the projectile's ogive.</li> <li data-xf-list-type="ul">= length of the head (ogive) in number of calibers.</li> </ul><p><strong>or</strong></p><p></p><p>A drag coefficient can also be calculated mathematically: </p><p></p><p><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/ddba6fc22c7dc567102336b8dd3662656e3d681e" alt="" class="fr-fic fr-dii fr-draggable " style="" /> <a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-8" target="_blank">[8]</a></p><p>Where:</p><p></p><ul> <li data-xf-list-type="ul"><em>Cd</em> = drag coefficient.</li> <li data-xf-list-type="ul"><em><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/1f7d439671d1289b6a816e6af7a304be40608d64" alt="" class="fr-fic fr-dii fr-draggable " style="" /></em> = density of the projectile.</li> <li data-xf-list-type="ul"><em>v</em> = projectile velocity at range.</li> <li data-xf-list-type="ul"><em><a href="https://en.wikipedia.org/wiki/%CE%A0" target="_blank">π</a> (pi) ≈ 3.14159</em></li> <li data-xf-list-type="ul"><em>d</em> = measured cross section (diameter) of projectile</li> </ul><p><strong>or</strong></p><p></p><p>From standard physics as applied to "G" models:</p><p></p><p><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/cc12a18710a7be27905af4dc4fed62c5e8bf3cd9" alt="" class="fr-fic fr-dii fr-draggable " style="" /> <a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-historical-9" target="_blank">[9]</a></p><p>Where:</p><p></p><ul> <li data-xf-list-type="ul"><em>i</em> = Coefficient of form.</li> <li data-xf-list-type="ul"><em>CG</em> = drag coefficient of 1.00 from any "G" model, reference drawing, projectile.<a href="https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-10" target="_blank">[10]</a></li> <li data-xf-list-type="ul"><em>Cp</em> = drag coefficient of the actual test projectile at range."</li> </ul></blockquote><p></p>
[QUOTE="Jed Eckert, post: 1717394, member: 111377"] Thanks for your time. Currently I'm using barnes 150 ttsx out of a .30-06 for blacktail deer and pigs to 500 max. Plan on going to barnes 175 lrx and adding elk in the coming year. For whatever its worth on wikipedia, It looks like Mass is an integral part of the equation, I should have looked it up before I asked. Projectile diameter and the shape of the projectile and are also very important. "The formula for calculating the ballistic coefficient for small and large arms projectiles [I]only[/I] is as follows: [IMG]https://wikimedia.org/api/rest_v1/media/math/render/svg/b109f3d8f77f6ebfe2df5de92e84d5614b7bee8c[/IMG] [URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-2'][2][/URL] Where: [LIST] [*][I]BCProjectile[/I] = ballistic coefficient as used in point mass trajectory from the Siacci method (less than 20 degrees).[URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-3'][3][/URL] [*][I]m[/I] = mass of bullet [*][I]d[/I] = measured cross section (diameter) of projectile [*][I]i[/I] = Coefficient of form [/LIST] The Coefficient of form ([I]i[/I]) can be derived by 6 methods and applied differently depending on the trajectory models used: G Model, Beugless/Coxe; 3 Sky Screen; 4 Sky Screen; Target Zeroing; Doppler radar.[URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-4'][4][/URL][URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-Rinker_1999_176-5'][5][/URL] Here are several methods to compute [I][B]i[/B][/I] or [B]Cd[/B]: [IMG]https://wikimedia.org/api/rest_v1/media/math/render/svg/2df3e7203bb0990c6ffeaad0ddee527b6d8fd6dd[/IMG] [URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-Cline_2002_44-6'][6][/URL][URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-Rinker_1999_176-5'][5][/URL][URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-7'][7][/URL] Where: [LIST] [*][I]i[/I] = Coefficient of form. [*][I]n[/I] = number of calibers of the projectile's [URL='https://en.wikipedia.org/wiki/Ogive']ogive[/URL]. [/LIST] Where [I]n[/I] is unknown: [IMG]https://wikimedia.org/api/rest_v1/media/math/render/svg/2625845546a7b804c77799f5e40c3dd539fd655d[/IMG] [URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-Cline_2002_44-6'][6][/URL] Where: [LIST] [*][I]n[/I] = number of calibers of the projectile's ogive. [*]= length of the head (ogive) in number of calibers. [/LIST] [B]or[/B] A drag coefficient can also be calculated mathematically: [IMG]https://wikimedia.org/api/rest_v1/media/math/render/svg/ddba6fc22c7dc567102336b8dd3662656e3d681e[/IMG] [URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-8'][8][/URL] Where: [LIST] [*][I]Cd[/I] = drag coefficient. [*][I][IMG]https://wikimedia.org/api/rest_v1/media/math/render/svg/1f7d439671d1289b6a816e6af7a304be40608d64[/IMG][/I] = density of the projectile. [*][I]v[/I] = projectile velocity at range. [*][I][URL='https://en.wikipedia.org/wiki/%CE%A0']π[/URL] (pi) ≈ 3.14159[/I] [*][I]d[/I] = measured cross section (diameter) of projectile [/LIST] [B]or[/B] From standard physics as applied to “G” models: [IMG]https://wikimedia.org/api/rest_v1/media/math/render/svg/cc12a18710a7be27905af4dc4fed62c5e8bf3cd9[/IMG] [URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-historical-9'][9][/URL] Where: [LIST] [*][I]i[/I] = Coefficient of form. [*][I]CG[/I] = drag coefficient of 1.00 from any “G” model, reference drawing, projectile.[URL='https://en.wikipedia.org/wiki/Ballistic_coefficient#cite_note-10'][10][/URL] [*][I]Cp[/I] = drag coefficient of the actual test projectile at range." [/LIST] [/QUOTE]
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BC always better on lead core bullets vs. copper. Why?
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