Has anyone done any testing with the 183's in a 1-9? Mine should be done soon, 32" 1-9, I know Sierra recommends a 1-8 but didn't know if I could get them to stabilize in a straight 284.
Sierra 183's in a 1-9 twist
- Thread starter Cody Richardson
- Start date
Go to Bergers website they have a twist calculator on there and put the information in. That will give you an idea if they will stabilize or not. Here is the link: http://www.bergerbullets.com/twist-rate-calculator/
If you had a 1:8.5 I think you would be perfect.
If you had a 1:8.5 I think you would be perfect.
Lots of folks tend to forget that the some manufacturers, including Sierra, use computational and experimental techniques that are more accurate for their bullets than used by the Berger (and other common) twist rate calculators.
But at the same time, manufacturer recommendations tend to be for the worst case conditions (cold days at sea level). One can use slower twist rates under less dense atmospheric conditions. Using a 1 in 9" twist where a 1 in 8" twist is recommended at sea level would require an atmospheric density of (8/9)^2 of that at sea level, that's about 79%. If you shoot at a location where the atmospheric pressure is 79% of sea level, a 1 in 9" twist will provide the same stability as Sierra's recommendation at sea level.
But at the same time, manufacturer recommendations tend to be for the worst case conditions (cold days at sea level). One can use slower twist rates under less dense atmospheric conditions. Using a 1 in 9" twist where a 1 in 8" twist is recommended at sea level would require an atmospheric density of (8/9)^2 of that at sea level, that's about 79%. If you shoot at a location where the atmospheric pressure is 79% of sea level, a 1 in 9" twist will provide the same stability as Sierra's recommendation at sea level.
Dusty Stevens
Shiner
9 works fine at 250' elevation
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