I have and still use bismuth to create the same size jig except the jig is lighter. The difference between lead and bismuth is this:
Bismuth is lead free especially for some states that require lead free jigs.
You can pour bismuth at home without any problems, can't do that with tungsten.
Bismuth is about 1/3 less in weight than lead.
Bismuth is very hard, and if you cast it at a brick wall hard enough it will crack. However I never had this happen yet.
Bismuth has a low melting point, so if you intend to powder paint it, it can be very tricky. I suggest you rough it up, spray with self etching primer and air brush with lacquer.