John W
>This task is similiar to sizing a M&T joint by the width of your chisel. You make one to fit the other. It sounds like your drill bit may be a bit undersized. I have had this happen to me. I have a LN dowel plate and the only bits I have that will bore a hole with NO gap using the LN dowels are Russell Jennings bits that I use with a brace. If your hole is oversized drawboring will not close a gap.
Try another high quality drill bit.
Another trick is, if the pins go all the way through, put a piece of hardwood under the pin, then cut it about 1/16" proud on the face. Using a steel hammer peen the pin until it mushrooms to fill the gap.
Use hide glue, liquid or hot, it will best hide any gaps that are left. Good luck,
John