I would suggest using CTRL+X to lock your guns to a heading. You won't have to worry about keeping your R mouse button clicked and can move camera around freely. The plus to it as well is when your ship has torpedoes (Tirpitz, Most CA's). You can lock your guns to a heading you want them at, but freely use your torpedoes on other targets.
Another option, if you want your guns pointed at an area on the map (works well with ships with fast turrets) is SHIFT+X. It will lock your guns to a sector on the map.
These bindings actually work with torpedoes as well. You select torpedoes, then use one of the two key bindings mentioned above. Comes in handy when you want to torp something to your port, but have to shoot at something to starboard. You won't have to wait for the tubes/turrets to traverse as they will pretty much be spot on for a shot.
Mind you, those key bindings are the default. Adjust according to what you've set them to.
