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Bonner
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need advice on bullet for a 1-14 twist barrel
Apr 25th, 2019 at 8:18pm
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I had a barrel relined  in 32-40, it is a 1-14 twist. What weight bullet should I used and what mold. I will be breach seating the cast bullet. Thank for any help. Bonner
  
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frnkeore
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Re: need advice on bullet for a 1-14 twist barrel
Reply #1 - Apr 26th, 2019 at 2:35am
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This is the mold that I would suggest. It's a clone of a Paul Jones mold, for 14 twist.

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Frank
  

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Schuetzendave
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Re: need advice on bullet for a 1-14 twist barrel
Reply #2 - Apr 26th, 2019 at 4:53am
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The mold suggested by Frank is the maximum length bullet that can be used in a 14:1 twist.
At colder temperatures or during high pressure systems or reduced velocities the Sg (Gyroscopic Stability Factor) will go below 1.4.
Traditionally it was advised to use a 200 to 210 grain bullet in the 14 twist .32 calibers.

Caliber      0.321      Inches            
Bullet Weight      217      Grains            
Bullet Length      1.22      Inches            
Barrel Twist      14      Inches/turn            
muzzle velocity      1526      fps            
Temperature      50      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      1.41                  

Sg shouldn't be less than 1.4. 

« Last Edit: Apr 26th, 2019 at 4:58am by Schuetzendave »  
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Bonner
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Re: need advice on bullet for a 1-14 twist barrel
Reply #3 - Apr 26th, 2019 at 10:42am
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Thanks to frank and Schuetzendave for the info, ordered the mold this a.m. .Bonner
  
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