The time dependence of muon spin relaxation has been measured in high purity aluminum and silver samples in a longitudinal 2 T magnetic field at room temperature, using time-differential musr. For times greater than 10 ns, the shape fits well to a single exponential with relaxation rates of $lambda_{textrm{Al}} = 1.3 pm 0.2,(textrm{stat.}) pm 0.3,(textrm{syst.}),pms$ and $lambda_{textrm{Ag}} = 1.0 pm 0.2,(textrm{stat.}) pm 0.2,(textrm{syst.}),pms$.