Quick answer; first make sure your bullets fit your gun. For revolvers, measure the cylinder throats and slug the barrel. For pistols, slug the
barrel. I size my revolver bullets to the same diameter as the cylinder throats and my pistol bullets start out .002" larger than the groove diameter (this is the Reader's Digest version). This is an excellent article about casting and shooting cast bullets; From Ingot to Target: A Cast Bullet Guide For Handgunners, Table of Contents - Fryxell/Applegate For answers to any question regarding anything to do with cast bullets look around here; Cast Boolits