I made a great deal of shot, and when the "good" lead wheel weights were about gone, I quit.(Well, that and two torn rotator cuff surgeries, and a bad back)
I found that some of the newer w/w are magnetic, and can be sorted out with a magnet to the weight, and not just the clip.
Others are not magnetic, but may contain materials that melt at a higher temp. than lead, so controlling the temp when melting or re-melting may help a great deal.
As stated, beeswax in the melted lead, and skimming the surface many times, may help separate the metals.
Good luck
I found that some of the newer w/w are magnetic, and can be sorted out with a magnet to the weight, and not just the clip.
Others are not magnetic, but may contain materials that melt at a higher temp. than lead, so controlling the temp when melting or re-melting may help a great deal.
As stated, beeswax in the melted lead, and skimming the surface many times, may help separate the metals.
Good luck