Gunpowders are a type of explosive matter that belong in a category of propellants. Two types of gunpowders are distinguished by differences in their constituents, which are black powder and smokeless powders. Both of these propellants are prone to physical and chemical degradation. The degradation process is the most evident when gunpowders are exposed to conditions of elevated temperatures and moisture. Degradation has a negative impact on functionality and quality of gunpowders. This investigation offers a comparison of both types of gunpowders, in pristine state and aged state. Aging was simulated by exposing samples to different combinations of elevated moisture and temperature conditions. For the characterisation of samples in pristine and aged state, we used advanced spectroscopic, structural and thermal methods (HPLC, FTIR, SEM, DTA, TGA) as well as other conventional methods prescribed in OSRH. Experimental results point toward the difference of degradation susceptibility between different types of gunpowder. The aging and degradation of gunpowder predominantly occur due to chemical reaction with water from surrounding air. Despite the value of the constant for the rate of the degradation process is not significant, special attention has to be devoted to ensure proper conditions of gunpowder storage.