Are you drilling the ball? Map out the span as usual, line up the thumb with your regular size bit and pitches, then take it out and put the outer sleeve bit in the chuck and drill the hole.
OR
The outer sleeve is 1/16" thick, and the inner sleeve is 1/16" thick = 1/8 total. The slug is 1 1/4". Half of 1 1/4" is 5/8" plus 1/8"= 3/4" from the center of the slug to the outer.
Clear as mud!!??
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Corey Clayton
Brunswick Amateur Staff
Turbo Grips Staff
Team Canada 2007, 2008, & 2009