I thought it was amusing that the guy with the blond crewcut didn't have his ear protection on for the first shot, then he put the muffs on for the reloading procedure. Maybe he thought he wasn't in view for the early part of the video.
There was a scene in the Steven Seagal movie Under Siege showing the firing of one of a battleship's main guns. They showed the process of loading and charging the gun. It wasn't quite as automated, IIRC. I think they had to load each bag of powder individually -- and I think they only used three, not six.
I don't remember if they showed loading it in Battleship.