In this comparative study, a solid composite, AN/HTPB-based propellant was prepared by conventional processing in a mechanical mixer and by applying an advanced processing technique relying on resonant acoustic mixing (RAM). After curing of the propellants, cross-sections were prepared and characterized by scanning electron microscopy. Also the density of the propellants was measured and finally the ballistic properties were measured using chimney burner tests. The experimental results clearly showed that the oxidizer particles, the homogeneity of the propellants, the density and the burn rate properties are hardly affected by the processing method. For the propellant studied in this research, resonant acoustic mixing is a very promising, advanced processing technique that can be applied as an alternative to the conventional mechanical mixing of this high solid load propellant composition.