  This paper presents a systematic evaluation of the ability of theoretical
models to reproduce experimental Gamow-Teller transition strength distributions
measured via (n,p)-type charge-exchange reactions at intermediate beam
energies. The focus is on transitions from stable nuclei in the pf shell
(45<A<64). The impact of deviations between experimental and theoretical
Gamow-Teller strength distributions on derived stellar electron-capture rates
at densities and temperatures of relevance for Type Ia and Type II supernovae
is investigated. The theoretical models included in the study are based on the
shell-model, using the KB3G and GXPF1a interactions, and quasiparticle
random-phase approximation (QRPA) using ground-state deformation parameters and
masses from the finite-range droplet model.
