Just found another really nice source...
I am in the "bioscence" profession, and I've found that the isotopes used for radiodiagnostics and radiotherapy are shipped in nice lead containers that are afterwards discarded....
I'll see if I can get my hands on them.
I've done some really scientific tests (using a Bic pen) on the recycled bulletts and can confirm that the lead obtained from jacketed bulletts is the softest one available, while bare and electroplated bulletts are definitely harder.
I have been told (but I have yet to check it, so take it as it is worth) that bare lead and electroplated bulletts: a) need to be harder; b)are molten, therefore some other metals in the alloy lower the melting point . while the lead core of FMJs is cold pressed therefore there is no need to have something to lower the melting point and there is no need for a hard alloy aswell.