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heat762
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Posted: 1/29/2012 11:01:04 AM EST
[Last Edit: 2/3/2012 8:50:11 AM EST by heat762]
Gents, has anyone ever chronographed the muzzle velocity of federal tru 64 grain sp out of a 10.5 barrel with 1/9 twist? Would be a big help.

EDA: A nice guy at the range let me run 10 rounds through his chrono. Below are the number.
Avg: 2368
Hi: 2412
Low: 2333
Extreme Spread: 78.8
Standard Dev: 24.4
Average Dev: 18.4

This was out of a factory Rock River SBR, 10.5", 1/9 twist, Chrome lined barrel,
65 degrees outside, 160 elevation

Enjoy
heat762
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Posted: 2/3/2012 8:50:48 AM EST
BTT with actual numbers
Shermantor-AR15
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Posted: 2/3/2012 9:38:16 AM EST
Here is some chrono results from my 10.3" DD 1/7 twist barrel. Using IMI M855

IMI Factory 5.56 62gr SS109 FMJ
Average2655.9
High2682
Low2618
Standard Deviation19.19172275
Extreme Spread64
Energy971.3395039


12618
22662
32669
42654
52668
62638
72661
82682
92638
102669