Another job you might want to do: testing aircraft gun turrets (British method)

R. Wallace Clarke.  British Aircraft Armament.  Vol 1.  RAF Gun Turrets from 1914 to the
Present Day.  Patrick Stephens Ltd., 1993.

Fraser Nash FN20 rear turret  in a testing bay at Yate, from an original painting by Terence Cuneo, OBE, RGI.