Thanks Eswube!
The 5.25 turrets were really rather cramped, which interfered with the firing rate, although this might be alleviated somewhat by using a smaller gun with lighter ammunition. If anything, you could try and make them somewhat larger
That's a fair point, I'll look in to size options. My original design was smaller still but the current one has ended up being the same length and width as the 5.25in but taller - adding 1 pixel would give it the same length as the post war 4.5in and the 5.25in on the HMS Vanguard drawing, while adding 2 pixels would give it the same length as the US 5in twin (though two of those turrets are square shaped rather than circular like mine).