 |  | | | |  | |  |  | gain twist ... |  | |  |  | |
 Posted: Sat Feb 18, 2012 6:08 am |
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| GoodEnough |
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Gain Twist does not have to start from smooth bore to. It is the actual "rate of twist" that is given the discription 'Gain twist' when it speeds up to a higher rate of twist. Like forcing a spinning projectile to spin faster toward the muzzle (or starting the spin from zero as in a 'smoothbore')
Gain twist is when any rate of twist increases from starting point to exit.
This is what I always thought it was ...
Don't lynch me if it isn't though.
Pete |
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| Posted: Sat Feb 18, 2012 9:29 am |
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| rsterne wrote: |
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That's correct. Exaggerated view but correct.
For example: A .177 going from a dead straight rifling at entry point to a 1:12 twist only changes the land engagement by atan(pi*.177/12) = 2.65 degrees. That translated into only about .0115" difference between two points 1/4" apart. |
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It's never too late to have a happy childhood. |
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| Posted: Sat Feb 18, 2012 11:16 am |
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| rsterne |
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Still, 0.0115" is significant when you consider that a rifling land on a .177 is probably only twice that....
On a .30 cal Pointed benchrest bullet where the engagement surface is likely over 1/2" long it would be over 0.040", which would be wider than the lands.... meaning that the groove carved would be probably 0.080".... to me that's pretty significant....
but if it works, who am I to argue.... 
Bob |
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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count! |
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| Posted: Sat Feb 18, 2012 11:32 am |
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| SMP |
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| Well it could be safe to say it doesn't work in our application. My gut tells me it would be a complete not starter on something as delicate as a pellet. |
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Sean
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| Posted: Sat Feb 18, 2012 11:57 am |
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| rsterne |
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_________________
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count! |
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| Posted: Sat Feb 18, 2012 4:20 pm |
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| Joined: 13 Nov 2011 |
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| Maybe right guys. Think it would skid? Or are you thinking blow by? |
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It's never too late to have a happy childhood. |
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| Posted: Sat Feb 18, 2012 4:41 pm |
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| SMP |
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| Joined: 04 Feb 2011 |
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| Location: Just south of "Out There"- Land O Lakes Ontario |
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| Well the skid/smear that would inevitably upset a pellets rather dainty disposition with regards to stability |
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Sean
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