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16" 6X45 VELOCITES


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#1 ONLINE   GLShooter

GLShooter

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Posted Feb. 14 2014 - 06:12 PM

ROPO68: Sep 18, 2012 at 2:53pm
 
I am looking for the velocities you guys are achieving out of 16" barrels with 85g-100g loads. I have a 20" 6x45 and want to get an idea of how much velocity I am loosing by building a 16" upper.
 
I am currently shooting right over 2700 fps with 100g SBT and XBR 8208 powder loaded in PRI mags at 2.30 COAL out of the 20" 1:9 twist.



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#2 ONLINE   GLShooter

GLShooter

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Posted Feb. 14 2014 - 06:12 PM

I am looking for the velocities you guys are achieving out of 16" barrels with 85g-100g loads. I have a 20" 6x45 and want to get an idea of how much velocity I am loosing by building a 16" upper.
 
I am currently shooting right over 2700 fps with 100g SBT and XBR 8208 powder loaded in PRI mags at 2.30 COAL out of the 20" 1:9 twist.
 
Figure 125 FPS loss approximately.
 
 Per ACCURATE on the 6X45 compard to a 24" tube: For shorter barrels reduce velocity below as follows(ca): 20" -3.5%/-105Fps// 16" -8.2%/-244Fps
 
I did the reverse math for you and came up with right on 2570 + or -.  Oddly enough my 87 grain HPBTM bullets in my 20" 6X45 run right with the numbers on the Accurate sight compared to the 17 1/2" one of my wifes' that is pictured in my posting.
 
Greg


#3 ONLINE   GLShooter

GLShooter

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Posted Feb. 14 2014 - 06:14 PM

GLSHOOTER:  Sep 22, 2012 at 1:03pm
 
Mine:
 
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SIERRA90FMJMAGFED.jpg
 
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I haven't shot anything above a 90 though I do want to try the Berger 95's and if they shot I'll use them at 500 and 1000.  I personally believe that the 6X45 just won't handle anything bigger with adequate velocity for my usage.
 
Have you tried these loads in that 1:10 twist extra BHW barrel you got initially?
 
Greg





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