  The running-mass inflation model, which has strong motivation from particle
physics, predicts density perturbations whose spectral index is strongly
scale-dependent. For a large part of parameter space the spectrum rises sharply
to short scales. In this paper we compute the production of primordial black
holes, using both analytic and numerical calculation of the density
perturbation spectra. Observational constraints from black hole production are
shown to exclude a large region of otherwise permissible parameter space.
