I have mine drilled 3- 3/8 x 6-1/4 x 2-3/4, for sharp break point. I do however have the CD at the house for Core Tech members. When I get home this evening I'll e-mail some of the "exotic" drilling patterns he suggests for the WOMB. The above drilling gives me good length ( changed finish to 800 ) and a sharp but predictible break point.