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9 o'clock vs. 3 o'clock wind drifts different with same wind velocity???

 
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  #113  
Old 02-19-2012, 08:04 AM
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Re: 9 o'clock vs. 3 o'clock wind drifts different with same wind velocity???

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Originally Posted by Topshot View Post
Maybe someone might like to chip in and explain why a bullet drifts right with a right twist barrel?
It's called "gyroscopic precession."

Precession - Wikipedia, the free encyclopedia

A well balanced bullet keeps its spin axis parallel to its trajectory. You can see this best by watching a football that's passed and spins perfectly. It noses over throughout its trajectory just like bullets do.

As the long axis of a right-hand spinning bullet keeps pointing down from the bore axis it was fire at, that causes the bullet to point to the right. Left-hand twisted bullets "precess" to the left.

Note that football has a tiny bit of spin drift, too, but it's barely noticable. You can feel and see this happen as follows. Power up your electric hand drill with a long, 3/8" bit in it. Holding the drill horizontally then quickly point the bit down. Notice the force applied that tends to make the bit point to the right. If your drill's a reversable one, change it to reverse then do this again and note which direction the bit points to.
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  #114  
Old 02-19-2012, 12:26 PM
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Re: 9 o'clock vs. 3 o'clock wind drifts different with same wind velocity???

This is a question not a statement. where is a bullet getting its unevenly applied torque to cause the precession that causes the yaw that causes the drift
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  #115  
Old 02-19-2012, 12:29 PM
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Re: 9 o'clock vs. 3 o'clock wind drifts different with same wind velocity???

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Originally Posted by ken snyder View Post
Where is a bullet getting its unevenly applied torque to cause the precession that causes the yaw that causes the drift?
I don't think the torque's unevenly applied. But to some tiny amount, it may be. Below's web sites that explains the cause of spin drift. Bullet spin rate in rpm does slow down as it gets closer to the target. But the rate ain't nearly as fast as its velocity slows down.

Precession - Wikipedia, the free encyclopedia

http://bulletin.accurateshooter.com/...line-resource/

Last edited by Bart B; 02-19-2012 at 03:26 PM.
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