While answering a question about dowel sizes, I decided to post this here too,
Many dowel rods, and sometimes factory dowels, are undersized and don't fit in the normal sized holes properly. I suspect they just make them to the closest metric size. To make the problem worse, I have found that all bradpoint drill bits are not exactly the same. I have a nice set from Shopsmith, a set of B&D's, some from Sears.
To make sure my dowel stock or dowel is going to fit my holes, I have made a simple block of wood with the common size holes drilled in it with each set of drills I have, including forstner bits, and spade bits. Now, when I am looking for dowels at the store or at home, I just take the sample block with me and test the dowel.
I also bought an inexpensive set of over/under brad points. It has sizes 1/32 on both sides of the desired size. Pretty handy sometimes.
Rick Potter