DREAD has always looked like a silly system to me. You can either use energy to launch a single projectile, or us energy to spin the big apparatus, then release a single projectile. It just isn't energy efficient. Ammo is big and heavy, but so are batteries and deisel fuel.
Second thing that gets me. Spinning items tend to act awefully weird, almost like a gyroscope.
Read about early airplanes, like around ww1, basically the entire engine was spinning around a solid placment. A pilot could turn one way with ease, but turn the other way and WHAM total loss of control.