http://en.wikipedia.org/wiki/USS_Phoenix_%28CL-46%29
In the battle of Leyte Gulf, Phoenix was a unit of Rear Admiral Jesse Oldendorf's group which annihilated the Japanese Southern Force in the battle of Surigao Strait. Phoenix fired four spotting salvoes, and when the fourth hit, opened up with all of her 6" (152mm) batteries. The target later proved to be Yamashiro, which sank after 27 minutes of concentrated fire from the American fleet. The Japanese also lost Fusō and three destroyers in the battle, and American planes sank Mogami the next day.
Those 15 automatic 6” were supposedly pretty awesome once they found the range.