The three cannons on the CSS Pee Dee were each on a pivot and had a full 360 degree of fire. The ship itself was built for speed and maneuverability to act as a commerce raider and not to duke it out with a Union ship.
The Brooke cannons were for long range and the Dahlgren for short range. The Dahlgren fired a speical ball with a water resistant cap. The Brooke's had cannister shot. Those were also removed. The guns had been loaded when they were thrown overboard. These were removed while the cannons were still underwater.