Technical abstract 13.1-005 Today there is no sub-sonic ammunition currently type classified for use in the calibers provided by any DoD Service. Although sub-sonic rounds exist for some calibers, these rounds are not cost effective and exhibit excessive deviations in velocity (affecting accuracy), incomplete chamber sealing, absence of clean propellant burn, and inability to cycle the action on gas operated weapons. For 5.56mm, 7.62mm, and 0.338 calibers, we propose to investigate the feasibility of producing cost effective, functional and accurate sub-sonic rounds. This study will expand on a similarly focused feasibility study our company conducted during the year prior to the release of SOCOM13-005. We will reconsider the technical approaches that were rejected and critically review our proprietary technologies (Patents Pending) related to incorporating into the manufacturing process the rapid production of interior case volumes, optimal for sub-sonic calibers and projectiles. This feasibility effort will include evaluation of viability of polymer casings, case volume to projectile weight balancing, projectile shape, brass case interior sleeves, and propellant bonding. By recommending commercially feasible methods to manufacture reliable sub-sonic rounds, this study addresses a need to improve the survivability of Special Operations Forces and other Governmental Agencies in the Global War on Terror.