It's as the title says, a Quad big cannon setup, with a hoist based autoloader system.
The plan is, once Aeronautics becomes available, to mount it on a freespin bearing, which will allow for control of it's horizontal aiming.

I used the turret design from this map (https://www.planetminecraft.com/project/french-battleship-jean-bart-1-1/) of Battleship Jean Bart (as I was aiming to create a working version of the 380mm/45 Mle 1935 French Naval Gun), and then swapped out materials and minorly altered the shaping (walls for smoothing of rear curvature, other random tweaks) to modernize that design somewhat, and then squeezed my barrels and autoloaders into it.

For more pictures (because this website couldn't handle their files), here's link to my reddit post on the gun: https://www.reddit.com/r/CreateMod/comments/11b2ri2/create_big_cannons_autoloading_quad_turret_design/