5 Inch/54 Gun Ammunition

The 5 Inch/54 Gun Ammunition program, as outlined in Navy Budget Line Item 0250, is dedicated to the procurement and sustainment of ammunition for the MK 45 gun system installed on Navy cruisers and destroyers. The primary objective of this program is to ensure the availability of conventional 5/54 caliber ammunition and Counter Unmanned Aerial Systems (C-UAS) Hypervelocity Projectile (HVP) rounds to support operational requirements, training, and fleet readiness.

This ammunition is essential for engaging air, surface, and shore targets, and supports both routine fleet operations and contingency missions, including those under CENTCOM and Israel Security Supplemental authorities. The program encompasses several specific procurement goals. Conventional 5/54 ammunition items procured include propelling charges, high-explosive projectiles, multi-option fuzes, and inert training rounds. These components are vital for maintaining the Navy's capability to conduct surface warfare, air defense, and shore bombardment.

The program also funds the acquisition of advanced C-UAS HVP rounds, which are designed to counter emerging aerial threats and enhance the Navy's defensive posture against unmanned systems.

The Product Improvement Program is a critical element funded in the FY 2026 baseline to address supply chain challenges and ammunition obsolescence. This initiative focuses on reestablishing domestic production capability and qualifying modernized designs for both projectiles and propelling charges. Key efforts include the implementation and testing of Austempered Ductile Iron (ADI) for projectile bodies and domestically-sourced flowformed steel cartridge cases as replacements for obsolete components. These improvements are intended to create a more resilient and economical industrial base while maintaining or enhancing ammunition performance.

The Renovation Program is another major objective, aimed at restoring legacy ammunition assets to fleet-issuable condition. This involves the renovation of unserviceable projectiles and propelling charges, using spare components and existing assets to expedite inventory replenishment. Specific tasks include the safe removal and disposal of fuzes and explosive fills, structural certification, and refurbishment of exterior features. The renovation approach is cost-effective and necessary to address critical inventory shortages resulting from recent production line shutdowns and increased demand for other munitions.

Gauge Requirements and Production Engineering are also funded to support the quality assurance and metrology needs of the ammunition program. These activities ensure that all procured and renovated rounds meet stringent dimensional and performance standards, and provide ongoing engineering support for new acquisitions and production restart efforts. The procurement of auxiliary and test equipment is essential for maintaining the reliability and safety of ammunition supplied to the fleet.

CENTCOM C-UAS HVP efforts are specifically funded in FY 2024 through supplemental appropriations, supporting the procurement and integration of HVP rounds, warheads, and projectile data links. These efforts are in direct response to operational requirements in CENTCOM and allied support missions, enhancing the Navy's capability to counter unmanned aerial threats in high-risk environments.