Steve,
Yes, I get what you're asking, and I think you are vastly underestimating how much larger the turrets are as the shell gets bigger.
Now, here's how I THINK the empties were handled on these ships. When the breech opened and the spent case was ejected, my guess is that it fell into a trough under the breech and was pushed forward and out of the turret by some sort of hydraulically operated mechanism.
The 5" guns were loaded manually, with automatic ramming. Since the shells and cartridges could be handled by one person, you could make things a little tighter than they normally would be otherwise.
In this picture you get a pretty good idea as to how deep the turrets were on the Rodney and Nelson. The turret had to be this deep to allow for both the gun and the heavy shell handling equipment that was needed.
This picture also gives a very good idea as to the overall size of the turrets vs. guns (this is the USS Delaware, which used the same guns as Connecticut).
Obviously, the largest guns needed the deepest turrets.
In the case of the Connecticut, whose picture I posted, gun protrusion into the turret was probably about 10 feet.
In this line drawing, you can get an idea for the overall size of the turret, and extrapolate just how much of the breech and gun is in the turret.
Overall bore length of these guns was 45 feet. I'm not 100% clear on whether that length included the breech mechanism or not, but I think it did.
Given that, with the larger guns, I'd say that the gun takes up no more than 50 to 60% of the overall depth of the turret. The other 50% is filled to the brim with men and equipment.
I'll see if I can dig up some other photos showing the interior of a turret.
All photos linked from
www.warships1.com, the best ship site on the web.