[IMACmike]

for the rotation movement of the drum "bomb rack", you could use a pawl mechanism similar to how the cylinder in a revolver works (see Samual Colt's 1873 patent, for his pistol). Your CAD drawing is pretty cool, too. The key to this thing's market potential, in my opinion, will be its size, weight and what it drops. Personally, paint balls would be cool for a precision "bomb" drop.