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<blockquote data-quote="goodgrouper" data-source="post: 89831" data-attributes="member: 2852"><p>Sorry to say this but want you want does not exist.</p><p>Since velocity is a direct result of pressure, any magical coating or process of manufacturing that would reduce pressure on a 90 degree day would also reduce pressure on a freezing day thus giving you velocity reductions from faster to slower. In essence, how can a powder change it's burn rate or desired pressure(all by itself) while inside the bottle while maintaining a specific wanted velocity when the temp has now dropped 58 degrees?</p><p></p><p>Getting back to velo being a result of pressure, there are many many things that influence pressure. To name two that are relevant here are ambient air temps, and ambient temperature of the steel used in the action and barrel. As the temperature of your steel climbs from sunlight, air temp, or residual heat from previous shooting, the ability of it to increase pressure also increases. <font color="blue"> <em>No powder available to citizens of this country can change this simple fact.</em> </font> </p><p></p><p>Ever notice while chronographing that if you let a cartridge sit in a chamber (that has already been heated up from previous shooting) for several minutes that normally shoots standard deviations in the single digits, that it will spike up in velocity? THis is a direct result of higher temperature barrel steel causing internal pressures to rise. If your barrel goes from stone cold freezing to too hot to touch, it may have had the outside temperature raise 100 degrees or more. So when the ambient air temp changes your barrel steel temp from 32 to 90, it also changes the internal pressure proportionately which in turn increases your velocity! </p><p></p><p>All the magical coatings and fairy dust in the world cannot do a thing to change this to a degree that would make enough difference to us.</p><p></p><p>Only in the world of marketing and advertising developers does this basic principle of internal ballistics not exist.</p><p></p><p>Or in other words: WHen using Hodgdon, IMR, VV, Win, Ramshot, ALliant, Accurate, or any of the others, <font color="red"> you must find a suitable load and alter it slightly with the changing seasons. </font> </p><p> Some change more, some change less based on their composition and exposed surface area, but the bottom line is that they ALL change.</p><p></p><p> Sorry to be the bearer of bad news, but this might save you from spending money on miracle gimmicks and chasing your tail. /ubbthreads/images/graemlins/frown.gif</p></blockquote><p></p>
[QUOTE="goodgrouper, post: 89831, member: 2852"] Sorry to say this but want you want does not exist. Since velocity is a direct result of pressure, any magical coating or process of manufacturing that would reduce pressure on a 90 degree day would also reduce pressure on a freezing day thus giving you velocity reductions from faster to slower. In essence, how can a powder change it's burn rate or desired pressure(all by itself) while inside the bottle while maintaining a specific wanted velocity when the temp has now dropped 58 degrees? Getting back to velo being a result of pressure, there are many many things that influence pressure. To name two that are relevant here are ambient air temps, and ambient temperature of the steel used in the action and barrel. As the temperature of your steel climbs from sunlight, air temp, or residual heat from previous shooting, the ability of it to increase pressure also increases. <font color="blue"> [i]No powder available to citizens of this country can change this simple fact.[/i] </font> Ever notice while chronographing that if you let a cartridge sit in a chamber (that has already been heated up from previous shooting) for several minutes that normally shoots standard deviations in the single digits, that it will spike up in velocity? THis is a direct result of higher temperature barrel steel causing internal pressures to rise. If your barrel goes from stone cold freezing to too hot to touch, it may have had the outside temperature raise 100 degrees or more. So when the ambient air temp changes your barrel steel temp from 32 to 90, it also changes the internal pressure proportionately which in turn increases your velocity! All the magical coatings and fairy dust in the world cannot do a thing to change this to a degree that would make enough difference to us. Only in the world of marketing and advertising developers does this basic principle of internal ballistics not exist. Or in other words: WHen using Hodgdon, IMR, VV, Win, Ramshot, ALliant, Accurate, or any of the others, <font color="red"> you must find a suitable load and alter it slightly with the changing seasons. </font> Some change more, some change less based on their composition and exposed surface area, but the bottom line is that they ALL change. Sorry to be the bearer of bad news, but this might save you from spending money on miracle gimmicks and chasing your tail. [img]/ubbthreads/images/graemlins/frown.gif[/img] [/QUOTE]
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