Replacing Key Leads

[Newton Hunt]

>  including old printer's type, which included an impurity
>  which may have been antimony, which is the culprit.

As an old former printer I can assure you that antimony is not the
culprit.  Antimony is put into the lead because when molten it is
smaller than when solid therefore counteracting the shrinkage of lead
as it cools.  The thickness of a casting must not be allow to shrink. 
Antimony is fairly stable and far less prone to oxidation than lead. 
Considering that printer's lead has been around for some two to three
hundred years and STILL the same size indicates it's inherent
stability.

Lead used to cast bullets are also quite stable.  No one can afford to
use bullets that increase in caliber beyond the bore of the gun.

You have to look elsewhere for such problems.

		Newton
		nhunt@optonline.net