We have measured the electrical resistivity between 4.2 K and 300 K and longitudinal and transverse magnetoresistance at 4.2 K of several Ni, Co and Fe based alloys containing variouss,pimpurities such as Sn and Sb. The deviations from Matthiessen’s Rule (DMR) derived from the resistivity data have been fitted to the two current models of Campbelletal. and values for &agr; (the ratio of spin up to spin down resistivities at the impurity site), &mgr; (the same ratio at host sites) andD(the coefficient of spin mixing scattering events) estimated. These data yield values of &agr; close to one, as expected from a simple non‐magnetics,pscreening state around such impurities. The magnetoresistance data also yield values of &agr; close to 1, but there are consistent differences between these data and the two current model predictions with &agr;=1, especially for the Ni and Co based systems.