The original eight- or nine-gun battery carried about 1,600-1,800 six-inch rounds, alongside ammunition for the anti-aircraft guns. Replacing those weapons with 4.7-inch and four-inch guns changes the amount of ammunition the same spaces can hold. The working allowance for the conversion is roughly 1,800-2,400 replacement rounds. These are rough capacity estimates supporting the proposed reuse of the magazines.
Notable Point · 57:32-58:58
Reusing the six-inch ammunition magazines
Smaller replacement ammunition could fit the old magazines without rebuilding the ship's internal ammunition spaces.