The residence time distribution in magnesium beds was found to strongly depend on the properties of the used magnesium turnings and the operational conditions. Axial dispersion could be reduced by using finer magnesium turnings. The characteristics of the pump were also found to have an influence on the residence time distributions. Strongly and regularly pulsating pumps were found to lead to narrower residence time distributions in a packed bed reactor. The general applicability of using superimposed oscillating flows to influence axial dispersion in randomly packed beds of metal turnings was successfully demonstrated. In the case presented, magnesium turnings are used, but the concept should be easily transferable to other packed beds of metal turnings. To minimize the axial dispersion, a fine-tuning of oscillation amplitude and frequency to the properties of the packed bed is required.