Like mechg's original, this is designed to be spiral printed. I printed this on a Rostock Max v2 at 0.2mm layer height, 0.4mm wall thickness, scaled 2.5x, sliced using Cura, printed in clear ABS at 50mm/s at 235C. The result is about 15 inches tall.
I intend to fill it with m&m's as a christmas gift.
The openscad file cuts mechg's original object into the two pieces, narrows the nose cone at the base for the overlap, and adds the cutouts to provide support to the area with the diameter change.
The included rocket2_fixed.stl is the original shape cleaned with netfabb.
There are two tops: rocket3-top has a solid base. rocket3b-top has a hole in the base.