Practical 4.7-inch versus 4.5-inch rates of fire

Would the 4.5-inch gun's higher nominal rate of fire overwhelm the 4.7-inch gun's heavier shell during a twenty-minute destroyer engagement?

Not by the simple headline calculation: crew fatigue, manual loading, ship motion, and accurate fire reduce the sustained difference, while the 4.7-inch shell retains advantages in range and effect.

The prompt calculates that a one-round-per-minute advantage across six guns could produce 120 extra shells in twenty minutes. That arithmetic assumes a manually loaded mounting can sustain its peak rate throughout the engagement. The slightly slower 4.7-inch rhythm may be easier to maintain as fatigue accumulates, while its heavier shell carries farther and has more effect. Ship motion, target tracking, and accurate fire widen the gap between a controlled trial figure and combat output. Practical firepower depends on crew endurance, sea conditions, shell performance, and nominal rate of fire.