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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Has anybody tried the 200 grain Berger Hybrid in 308 Win?
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<blockquote data-quote="Gerard Schultz" data-source="post: 949775" data-attributes="member: 51"><p>From this page:</p><p><a href="http://www.gsgroup.co.za/faqbullettwist.html" target="_blank">GS CUSTOM BULLETS - Twist Rates and Bullet Length</a></p><p></p><p><em>"At a muzzle velocity of 1600fps and a barrel twist rate of 1:10", the stability factor (Sg) is 1.25. </em></p><p><em></em></p><p><em>An increase in muzzle velocity results in an increase of the Sg and, going from a muzzle velocity of 1600fps to 3600fps, results in an increase of the Sg to 1.34.</em></p><p><em></em></p><p> <em>A difference in twist rate of half an inch, up or down, will influence the Sg as follows: At a twist rate of 1:10.5" and at a muzzle velocity of 3600fps, the Sg is 1.215. At a twist rate of 1:10" the Sg is 1.339. </em></p><p><em></em></p><p><em>So, increasing the twist from 1:10.5" to 1:10", increases the Sg by 0.124 and has a greater effect on the Sg than an increase of muzzle velocity from 1600fps to 3600fps. It is quite clear that a twist/bullet length mismatch cannot be fixed by adjusting the speed. A 2000fps increase in speed has less value than a half inch difference in twist rate."</em></p></blockquote><p></p>
[QUOTE="Gerard Schultz, post: 949775, member: 51"] From this page: [url=http://www.gsgroup.co.za/faqbullettwist.html]GS CUSTOM BULLETS - Twist Rates and Bullet Length[/url] [I]"At a muzzle velocity of 1600fps and a barrel twist rate of 1:10", the stability factor (Sg) is 1.25. An increase in muzzle velocity results in an increase of the Sg and, going from a muzzle velocity of 1600fps to 3600fps, results in an increase of the Sg to 1.34. A difference in twist rate of half an inch, up or down, will influence the Sg as follows: At a twist rate of 1:10.5" and at a muzzle velocity of 3600fps, the Sg is 1.215. At a twist rate of 1:10" the Sg is 1.339. So, increasing the twist from 1:10.5" to 1:10", increases the Sg by 0.124 and has a greater effect on the Sg than an increase of muzzle velocity from 1600fps to 3600fps. It is quite clear that a twist/bullet length mismatch cannot be fixed by adjusting the speed. A 2000fps increase in speed has less value than a half inch difference in twist rate."[/I] [/QUOTE]
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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Has anybody tried the 200 grain Berger Hybrid in 308 Win?
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