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Rifles, Reloading, Optics, Equipment
Reloading
How do you lower S.D.?
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<blockquote data-quote="J E Custom" data-source="post: 188345" data-attributes="member: 2736"><p>KQguy</p><p></p><p>Standard Deviation spreads are effected by poor or inconsistant </p><p>combustion.</p><p></p><p>Some causes of this are low powder densities( 70% to 80%) wrong</p><p>primer choice,wrong powder choice, inconsistant powder charge and</p><p>poorly prepped brass.</p><p></p><p>And good groups with poor SD,s spell disaster at long range.</p><p></p><p>A good way to show this is run the balistics at the lowest velocity</p><p>with that load and then run the same test using the highest.</p><p></p><p>Just for kicks I ran the 7/08 at 3000ft/sec and added 60 ft/sec</p><p>to see what the spread was. and it came out to 14.2" @ 1000 yrds</p><p>under perfect conditions (enough for a bad hit or a complete miss at</p><p>long distance).</p><p></p><p>In cases with around 100gr or less capacity I have found times that </p><p>going to a standard rifle primer improved SDs but they also lost some</p><p>velocity (25 to 50 ft/sec).</p><p></p><p>Good luck on improving SD,s</p><p>J E CUSTOM</p></blockquote><p></p>
[QUOTE="J E Custom, post: 188345, member: 2736"] KQguy Standard Deviation spreads are effected by poor or inconsistant combustion. Some causes of this are low powder densities( 70% to 80%) wrong primer choice,wrong powder choice, inconsistant powder charge and poorly prepped brass. And good groups with poor SD,s spell disaster at long range. A good way to show this is run the balistics at the lowest velocity with that load and then run the same test using the highest. Just for kicks I ran the 7/08 at 3000ft/sec and added 60 ft/sec to see what the spread was. and it came out to 14.2" @ 1000 yrds under perfect conditions (enough for a bad hit or a complete miss at long distance). In cases with around 100gr or less capacity I have found times that going to a standard rifle primer improved SDs but they also lost some velocity (25 to 50 ft/sec). Good luck on improving SD,s J E CUSTOM [/QUOTE]
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Rifles, Reloading, Optics, Equipment
Reloading
How do you lower S.D.?
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