The 2nd part is an interesting problem. Print the barrel and drone casing together, so that you can eliminating syncing (/tying) the two together, which should

The 2nd part is an interesting problem. Print the barrel and drone casing together, so that you can eliminating syncing (/tying) the two together, which should enhance aiming significantly and allow you to link your software aiming to the hardware firing line a lot easier. Of course if the barrel can't turn, then the operator needs to select a body for the drone that matches its height to target, or that can accurately turn the drone body by a few degrees. Otherwise you need a bit of extra hardware that will be able to turn the barrel to a precise number of degrees. After that use a very basic onboard camera to id the target by a human operator. The drone can find the center of mass of the target object (e.g. head sphere), the operator confirms and then the drone merely flies close enough to eliminate missing and fires. The only issue of course being if the target is moving too much or is occluded at any point, at which time you'd need more advanced image recognition, or further operator adjustments.