Abstract : Black powder samples were compressed into parallelepipeds of several different densities. Strand burn rates of these samples were determined by high- speed cinematography at constant pressures to 100 atmospheres. The rate can be represented as r = 1.72 p0.164, with the regression rate, r, in cm/sec and pressure, p, in atmospheres. High-speed movies, 2000 frames per second, showed the combustion mode, droplet-particle formation, and images that were used to derive both surface and strand burn rates. Compaction of black powder meal was found to be in a linear logarithmic function of applied pressure, where samples of different moisture content formed a family of parallel lines. This same functional relationship was found when compressing grains of black powder and copper spheres. This similarity suggests the same physical processes are occurring in both materials where compaction results in plastic flow among a collection of close packed spheres.