The NEUT intranuclear cascade model is described and fit to a large body of<br />
\pipm--nucleus scattering data. Methods are developed to deal with deficiencies<br />
in the available historical data, and robust uncertainty estimates are<br />
produced. The results are compared to a variety of simulation packages, and the<br />
data itself. This work provides a method for tuning Final State Interaction<br />
models, which are of particular interest to neutrino experiments that operate<br />
in the few-GeV energy region, and provides results which can be used directly<br />
by the T2K and Super-Kamiokande collaborations, for whom NEUT is the primary<br />
simulation package.