Soft lead / cable sheathing
Hi all, I'm new to casting bullets but not to reloading, I have purchased a small furnace, a couple of molds and sizing dies, I have a couple of hundred pounds of lead cable sheathing I've saved through the last many years and wanted to cast bullets and powder coat,, I'm finding the mostly pure lead seems to cast out small; even with powder coating I'm having troubles with to small of a bullet such as casting for .452 and after sizing and coating i still measure out somewhere around .450/.451,, Is this because of the close to pure lead shrinking/contracting so much as it cools? I've added small amounts of foundry alloy(antimony/tin mix) to the lead sheathing and it seemed to cast out larger but I am trying to stay away from hardening and just stop leading by powder coating, Is this even possible?
My biggest problem seems to be the bullet is so small or coating is so slick that the bullet won't stay in place with tapper, profile or factory crimp dies (9mm and 45Acp); my .44 with roll crimp holds in place a little better.. I'm new and eager to learn,, thanks for any in sight ...