Cold Swaged V/S Cast Lead

[WingNut]

I am doing some homework getting ready to reload.  I haven't run a single load through a press yet.

 

Can anyone simply explain the difference in hardness between traditional "Cast" lead and Swaged?

I'm also looking for a BHN number for Hornady 158 gr .358 SWC.

 

Thanks in advance.

[Pygmy]

I have not had much experience casting bullets, except for a few muzzleloader prjectiles, and I am not a metallurgist although I worked for a period of time as a lab tech in an industrial metallurgy lab.

However, I was always of the assumption that the "hardness" of lead was determined by alloying, adding amounts of tin or antimony to pure lead to make it harder. Simple casting vs. swaging, as I understand the process, is merely a forming method, rather a method increasing hardness.