Boron carbide (10B4C) shields are frequently used in the measurement of fast- and intermediate-neutron spectra. In this Note, we present the results of both transport calculations and experimentally measured values for the transmission factors for various activation detectors when covered with a 1.65 g/cm3 10B shield. For unfolding work, the (n,α) absorption by 10B is calculated for each activation detector, and net correction factors are subsequently presented.