Abstract: A bowling ball drilling apparatus for drilling variable size holes includes a table having an upwardly opening ball supporting pocket. A boring apparatus is mounted below the table for reciprocation in a generally vertical direction in a path intersecting the pocket. A carriage moves the boring apparatus in the path. The boring apparatus has an output shaft rotatable about a vertical axis. An adjustable boring head is connected to the output shaft for rotation therewith, the boring head receiving a boring tool and being variable adjusted to offset the boring tool horizontally relative to the vertical axis so that the boring tool orbits about the vertical axis to produce a variable size hole in the bowling ball dependent on an amount of the offset.