Measurements are reported of the specific heat of 5 U.S. Army solid gun propellants over the temperature range — 40°C to 75°C at atmospheric pressure. The propellants are members of the BRL Research Series propellants that have been widely distributed to research laboratories in the U.S. These propellants include representative types from each class of materials that are either in the fielded inventory or experimental (“X” prefix), i.e., a single base (M10), a double base (M9), a homogeneous triple base (JA2), a composite triple base (M30), and a composite nitramine (XM39). The measurements were performed with a commercial differential scanning calorimeter (DSC) which was calibrated to the propellant heat-flow range using two sapphire standards of different masses. Corrections were made for temperature lags in both the standard and propellant specimens. The average values are estimated to be accurate to within ±5%, and polynomial fits over the stated temperature range are provided for convenient use in calculations