The technological status of a boron-slurry and the low-volume ramjet engines was reviewed. Engine performance maps including parametric variations of the critical assumptions were developed. Numerous preliminary designs of the ARM-II missile system utilizing each propulsion system were made. The range performance for a low-altitude, high-speed trajectory was calculated for each design and its parametric variations. The results show the boron-slurry engine offers a substantial range performance advantage over the low-volume ramjet engine for both the weight and volume limited cases.