Reply by CharlieM1958

They should be snug, but if they really don’t fit, either your dowel is too big (moisture or poor manufacturing), or your hole is too small. :-)

There is no need for a flat-bottomed hole since the dowels are not going all the way to the bottom anyway. A standard twist drill or brad-point bit will be easier to work witj, and a little wiggle when drilling will give you a bit bigger hole to accept the dowel.

-- Charlie M. "Woodworking - patience = firewood"