Benchmark experiments of neutron propagation in iron and iron-sodium mixtures were used to generate an “adjusted” ENDF/B data file for iron, Mat = 1192. In particular, the secondary neutron energy distribution in the continuous level energy range was adjusted using such high-energy responses as the 32S(n,p)32P reaction, which are significantly sensitive to changes in that probability distribution. The experimental analysis used carefully checked two-dimensional transport methods to avoid bias in the adjustment procedure due to inadequate calculational methods.