Blue is probably Babbet in your alloy.

Sinkers are not a very consistent alloy(IMO). I wouldget some different alloy. A lot of shooter's like pure lead, however I personally believe that good clean WW will do every bit as good of a job. Especially in a round ball because you are using a patch.

The alloy could be causing the wrinkle. Or the mold may not be hot enough. Tom.