You should be able to get higher caliber singles on smaller ships sooner to have
competitive range with ships of a higher class.

Think about all the BCs and BB1-3s that are such easy food because they need to be
opportunistic vultures to even get hits on the top dogs. Such tactics as 'slingshotting'
are meaningless when you're so well within the range of the ship you're shooting at
you'll need to dodge or survive 5 salvos before you can even manage to escape.

What I propose is having a lower level for the single cannons.
ie. If you could get a 15"x2b at level 80, you could get the same set single at lvl 60.

Think about it. You'll have the same range as someone higher up, but lower damage.
Range = Life, especially in GB. And a BB without range is just food.

I'd rather do less damage at competitive range than heavy damage at suicide range.