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Old 04-28-2009, 12:57 PM
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ar15barrels ar15barrels is offline
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Quote:
Originally Posted by xrMike View Post
Approximate group size: .866 - .223 = .643 inches
You can't reliably use 0.223" as the hole size in the target without first measuring an actual hole in the actual target you are measuring.
The actual hole left by a bullet is usually 0.020" or more smaller than the bullet diameter.
Therefore, groups calculated by subtracting FULL bullet diameter from a measured group size are not accurate.
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