Paul J. Adam wrote:
http://www.army-technology.com/projects/cl289/

gets you a jet-propelled UAV that's been in service for some time.

They're unusual - for most applications a prop seems to give better
endurance-range-speed tradeoffs - but not totally unheard of.

Props are more efficient at low speeds and low altitudes.

The Pentagon is still buying turboprop transports after all.

http://www.airforce-technology.com/projects/hercules/

-HJC