This is a Craig’s list post hudsonvalley.craigslist.org/clt/5149659352.html. What are these?
?training? of separately loaded guns (tubes held the powder bags)
Much like the weighted wood, or today’s rubber coated, training “ammo” used to teach handling procedures with out risking the breach of the weapon
The “powder charges” are turned in the shape of the aluminum shipping/storage containers used for most types of Navy ammunition, and these look to be for the 5"/38, and the 55 pounds would be about right for a 5"/38 projectile as well.
These may have been for display purposes, war bond drives, recruiting, or for use in testing in shipyards to see if the containers would fit properly in the racks in the magazine, or cycle properly in the ammunition hoists to/from the magazines to upper decks. Likewise to test the projectile and powder hoists from the upper handling room into the gun mount/turret.
I do not think these are regulation U.S. Navy Bureau of Ordnance items with a specific “Mark and Mod” designation, but were locally prepared by a shipyard, or possibly at the unit level.