Experimental results are presented which show how the electron drag on mobile dislocations varies with temperature, applied strain rate, and magnetic field. In both copper and aluminum the same functional dependence of the change in stress with magnetic field is observed, that is, the change in stress varies with the square of the field, and is independent of temperature and applied strain rate, for a given change in field. These results are compared with various models of electron dislocation drag, for the case where the dislocations move as underdamped oscillators. The observations are qualitatively consistent with the dislocations moving as underdamped oscillators, for the temperature range studied.