I worked in a machine shop for 35 yrs. In all those years I never had to drive in a dowel pin when the hole was reamed with an .0005 oversize reamer. Most dowels run to about a +.0002 for nominal size. Reaming one hole with the nominal size & the other with the +.0005 reamer establishes which side the dowel stays in & which side it "Slips" in & out of.The dowel could be tapped into the one remed with the standard & would slip freely in the one reamed +.0005. If you had to drive a dowel in a hole reamed +.0005" you must have been using a worn out reamer. You can about throw it through a hole reamed to +.001"
+1 on what Miller said. The part about a .001" oversize being pretty big is especially true when the pins are down in the 3/32" to 5/32" range.
