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There are three ways to answer that, which boil down to "no, no, kinda yeah."

1. These almost perfectly aren't "blanks." In small arms, a "blank" is a cartridge with primer and propellant but no projectile. Makes the gun go bang but throws nothing. The shells in the picture above are projectiles with no propellant or primer. No "cartridge" of any description is used, the propellant is stored separately in cylindrical 110 pound bags, 6 of which are required to fire the gun.

2. The black shells on the left of the image are armor piercing shells, the green ones on the right are "high capacity" aka maximum kaboom. They do carry a number of inert shells that are filled with sand instead of high explosives, those are for training, but they are painted blue. Again not "blank" because a projectile is fired, but they don't explode on impact, they just land with the force of a Corolla going mach 1.2.

3. Because this is on the tour route of a museum ship, these shells have either had their bursting charges removed to render them inert, or they are fiberglass replicas.

USS North Carolina hasn't really published much media to the internet, but the USS New Jersey museum has a very good Youtube channel. Head over there and my main main Ryan will tell you all about it. Compared to North Carolina, New Jersey is a couple years younger, a bit larger, and had a longer career. North Carolina is a WWII museum, New Jersey is mostly in her Gulf War trim.