450Bushmaster.net

I need some help guys. I recently purchased a 325 grn Lyman mold that is supposed to cast at .452. I'm using wheel weights and the bullets are measuring .4505. I called Lyman and they said I had to use their #2 recipe or I would have problems. Does the lead makeup make a difference in the size of bullet that drops out of the mold? Doesn't make sense to me but maybe it does. Any experience with this problem?

While that's a pretty standard excuse from Lyman, alloy composition and the temp you're casting at will both effect the "as cast" boolit diameter. Read a little at the site below for lot's of info on casting boolits. In addition there are several mechanical methods to increase the diameter of the boolits you're dropping.

http://castboolits.gunloads.com/

BD

sounds like this mold is a good excuse to take up powder coating

When you heat up metal it expands....depending on the alloy some will "shrink" more than others....that is why Lyman uses No.2 lead alloy as a common denominator for the size of a bullet in No.2 alloy....
One thing is try a different measuring tool some could be off .001" or more....