CParker,

Kent Tungsten Matrix is not in that chart. TM is a plastic polymer with finely ground tungsten mixed in to increase the density. It is a soft material. After shooting a hundred or so rounds in my old hammer doubles from the 1920s and 1930s, there are no scratches. The shotcups used in Kent TM loads are really nothing more than ordinary ones used for lead alloy shot.

Niklas