I have finally received my pin gauges to measure the bore on my 1861 Pedersoli Springfield Musket and the .577 is the largest one to fit in the bore. I have cast some Minie' balls with my Lyman 575213 OS mold so I need to know what sizer to buy to get the balls to drop in and shoot accurately. I think I have seen suggestions of .001 and .002 under bore size. I am assuming that that is under the bore diameter but I want to make sure that the ball will not get hard to insert when the barrel has already been fired and is 'dirty'.
Thanks,
Mike