Short‐period PcP amplitudes have been observed to vary by a factor of about 20 in the epicentral range 40‐85°. This behavior is due to the reflection coefficient at the core‐mantle boundary, which varies from a maximum of about 0.5 at an angle of incidence of about 65° to zero at an angle of incidence of about 85° (corresponding to an epicentral ranges of about 60‐90°). We present physical model experiments in which we study the effect of corrugations of the core‐mantle boundary on PcP amplitudes. We find that corrugations with 2‐50 km scale lengths would radically alter the amplitude‐range behavior of short‐period PcP, reducing its variation with range. The observed pattern of short‐period PcP amplitudes indicates that the core‐mantle boundary is smooth on these scales, with amplitudes less th