I just uploaded a new video about how to expand the diameter of a cast bullet. This can be really handy for testing out an antique gun before ordering a custom mold. In the video I expand a .452" diameter 255gr bullet to .459". The process is the same for any bullet. All you really need is a sizing die that is the size you want the bullet expanded to.
https://youtu.be/ziBZeUS1DCI