The USN no longer maintains the capability to support any naval gun over 155mm.
The bagged charges (or at least separate charge and projectile systems on the newer ones) exist because different amounts of charge are required behind different types of projectiles, and to be able to tailor the ballistic arc of the projectile as needed. Guns of 5” caliber or less are generally autoloading these days and use a unified projectile and charge as a metallic cartridge firing small arm does.
Oh, well…
Just put some railguns on her then!