At leeast the stufff advertised as HeviShot Classic Doubles shot is advertized to be tungsten+iron in a tin matrix. One can presume that the tin (Sn) is the soft matrix material and tungsten(W) and iron are what raise density of Sn-matrix to that of lead alloy shot.

I think I understand correctly that "niceshot" is same product of EcoTungstes as is HeviShot Classis Doubles. However, I would love to see convincing evidence of this.

Niklas