The U. S. Navy needs a medium-caliber (5-inch) ship-mounted gun that can deliver a payload to a range five times farther than the present capability. Such an increase in performance requires major design changes to both the gun and its ammunition. A gun which can shoot beyond the visible horizon needs additional support from subsystems which provide targeting information and assessment of battle damage to the intended target. <p>A system engineering approach to the fulfillment of this need is presented. The gun weapon system is characterized through a functional analysis of its component subsystems. From this analysis, an allocation of design requirements is made to the various subsystems. Of particular interest to this project were the gun itself, and the sophisticated ammunition which it fires. Trade studies involving the design alternatives for the gun and its ammunition were carried out within the context of the total system involving also the fire control and targeting subsystems. These design capabilities are compared to the top-level system requirements, then iteratively improved where necessary. The objective of this project was the establishment of the top-level design requirements for the gun and its ammunition. Additionally, a life-cycle cost appraisal was developed for the proposed design. / Master of Science