Did gun crews rotate the heaviest work?

Would gun crews rotate the men handling the heaviest ammunition and gun-running work?

No; sailors had assigned tasks, so the loader and other specialists repeatedly performed their particular part of the firing cycle.

The audience asks whether sailors rotated through the physically demanding tasks of serving a gun. Each person had an assigned role and did not shift casually between jobs. The loader repeatedly handled heavy shot while also helping clean, reload, and run the weapon during sustained firing. That specialization made individual physique and practiced teamwork part of a battery's effective rate of fire.