the present invention provides a liquid spray gun with several improved features , including a molded polymeric possibly disposable body assembly through which passes liquid sprayed by the spray gun that is manually releasable from a metal platform portion of the spray gun through which air is fed to passageways through the body assembly to spray the liquid ; non - cylindrical air passageways on air horns that provide improved shape and uniformity for the wide elongate stream of liquid formed by the spray gun , and an air cap portion of the body assembly mounted for manual rotation on a nozzle portion of the body assembly between positions defined by stops and retained at those positions by friction .