I second what Baddog said! Lots of good info on the cast Boolits forum!My first suggestion to a new caster is go to and join the "cast Boolits forum" ,and read.For the most part there are few internet Ex-Purts, and the advise you get to pretty sound.
When you say SCRAP, what are you talking about ? COW= clip on wheel Wts., SOW= Stick on wheel Wts. , ??
The BHN # of your alloy [scrap] won't tell you every thing you need to know about the usefulness of your material as it pertains to casting good bullets for your intended use ??
Ask on the "Cast Boolits forum" if there any casters in your area
This time of the year is a good time for gathering "alloys" and searching "thrift shops" for cast iron "Dutch ovens" ie; pots