Experimental methods which utilize incident bremsstrahlung radiation have been developed for rigorously evaluating gamma-ray shielding calculational methods and for determining gamma-ray shielding design parameters over a continuous energy span. Comparisons between experimentally determined double differential transmitted spectra, i.e., the spectra as a function of energy and angle, with corresponding calculated transmitted spectra, provides a rigorous test of the calculation. Additionally, by varying the maximum energy of the incident bremsstrahlung radiation, the kernel governing the angle and energy distribution of the transmitted photons can be unfolded from the spectra. A knowledge of this kernel allows calculations to be made of other parameters, such as build-up factors, transmitted doses, etc. Reasonably accurate kernels were obtained by subtracting out the contribution due to single collisions, and by smoothing the remaining multicollision component by applying Cook’s least structure analysis. To establish the methods, collimated beams of bremsstrahlung radiation were directed against an iron slab and the experimental results were compared to those obtained from the multigroup Monte Carlo code MORSE. Transmission measurements were taken at angles of 0, 30, and 60 deg from the incident direction. After modifying the estimator subroutine in MORSE, the spectral agreement obtained was excellent. The kernels obtained by inputting an incident constant group unit source in MORSE agreed favorably with those obtained experimentally from incident bremsstrahlung spectra.