  The concept of local homogenization is invoked in the visible and the
sub-visible frequency regimes to estimate the permittivity dyadics of a
thin-film helicoidal bianisotropic mediums (TFHBMs)~---~a canonical class of
sculptured thin films with helicoidally periodic microstructure~---~made of a
metal. Examination of the components of the permittivity dyadics, as well as of
the co- and the cross-polarized reflectances of axially excited, metallic TFHBM
halfspaces, reveals that three different absorbing-dielectric-to-metal
transitions will occur as the metallic volumetric fraction is increased, but
only two will be optically sensed using normally incident plane waves. The
first transition is show to virtually eliminate the circular Bragg phenomenon
characteristically displayed by axially excited, dielectric TFHBMs.
