View Single Post
Old 04-28-2009, 12:57 PM
ar15barrels's Avatar
ar15barrels ar15barrels is offline
I need a LIFE!!
Join Date: Jan 2006
Location: Van Nuys
Posts: 44,450
iTrader: 95 / 100%

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.
Randall Rausch

AR work:
Bolt actions:
Foreign Semi Autos:
Glock, XD and M&P pistols, Benelli and Remington shotguns: barrel, sight, trigger and receiver work.
Most work performed while-you-wait, evening and weekend appointments available.
Founding member of the CAPRC
Reply With Quote