I finally got a chance to cast using my new MP aluminum mould and ended with wrinkled bullets. I've tried different lead temperatures, heated the mould, cooled the mould, cleaned it twice with brake cleaner, even alternated between dipping and bottom pour. Finally, I switched to my old Saeco mould and got perfect bullets. The ones on the left are from the MP mould, the ones on the right are from the Saeco mould. I'm beginning to believe I'm not smart enough to cast with an aluminum mould. Any ideas would be appreciated.