If you make your own drill bit storage block, you can check the holes with bolts to check for size for drilling the pilot.
When I need to drill a pilot hole for a fastener or dowel, I select my bit using a fail-safe method: I store my bits in a block of hardwood labeled with each bit size. I used the drill bits themselves to bore their respective holes in the block. To find the right bit for the job, I take the fastener and use the block as a hole-sizing gauge. When the bolt just fits the hole, I know I’ve got the correct bit for drilling the pilot.
