One needs to clean the miniatures after taking them out of the box. Manufacturers put a powder or special spray in the molds to help the molds release their product.
(left) Take a hard bristle toothbrush and some dish detergent, scrub the miniature under warm water, when finished place the cleaned miniature on a towel to dry (right).
When dry, take an xacto knife and trim off the miniature any flashes or slag left by the mold and also lightly scrape off the seam lines. Be careful not to scrape to deep or hard for white metal & lead is very soft.