I was going over some old Muzzleloader mag's and in May/June 1998 issue there is a article by Darwin Johnston tilted "The Curse Of The Sprue." In it Darwin talks about the fact that the sprue on lead balls is a "Significant blemish on the surface of the ball that can seriously affect the location of the center of gravity, hence its balance, and consequently its accuracy." Darwin goes on and talks about why the sprue causes the lead ball to become unbalanced. As the ball rotates in the riffling and exits the barrel, this spiral action on the ball speeds down range with a unbalanced center of gravity (c.g.) will depart on a path tangent to the spiral. This tangential, a lateral departure from the center of the bore, influences the accuracy of the shot. Daren gives an example, "Using a rifle having a 48-inch twist and seated cast ball with its c.g. located at a distance from the center of the bore equal to the thickness of a piece of paper, 0.004 inches, the ball can be expected to strike no closer than 1.88 inches to an target 100 yards away." Stated more dramatically, Darwin states that this unbalanced ball will strike on the circumference of a 3.76-inch diameter circle centered on an aiming point 100 yards away. Also, patching, starting and ramming inconsistencies can affect the c.g. by as much as 0.015 inches from the center of the bore. Darwin goes into much math with "tables of predicted errors" and gives two conclusions. First, is having a rifle with a slow twist rate and states that "Perhaps this is why we often refer to rifles having a slower twist rate as ball guns," Second, given a choice, use cold swaged balls, or carefully trim the sprue from smooth, round cast balls before using them. After reading this article, my question is, what would you use to remove the sprue, a file, knife, etc?