A dual-purpose gun's ammunition choices

How many shell types can a dual-purpose naval gun use?

Often three or four, covering several target sets; programmable fuzes can let one shell type perform more than one role.

Modern four- to five-inch systems commonly carry three or four ammunition types. The mix can cover aircraft, surface ships, land targets, small boats, and illumination. A navy can also reduce the number of physical shell types by programming one fuze for different effects. The gun's dual-purpose label therefore understates the broader ammunition and fuze choices that let it serve several missions.