For years I have been simply gluing small squares of aluminum foil on one, or the other, or both faces of the mold block, with white glue, until the bullet diameter perpendicular to the parting line fit the throat for the best accuracy. This of course makes the bullet out of round but they shoot better than a round bullet that doesn't fit and even win a match now and again. The good thing is I can adjust the bullet diameter by adding more layers of foil and they are easily removed for reversing the process. The problem is the heat degrades the white glue and the foil spacers migrate around with use and sometimes fall off.
What materials are better for beagling spacers and glue?