F-89 turret

From May 1981 issue of "Airpower" magazine:

2. How the Martin turret worked. Originally programmed to carry a Northrop
designed rotatable turret in the XF-89, the Scorpion pursued that
possibility with the Martin turret. As shown in this company rendering, the
Martin turret carried four 20mm guns with 400 rounds per gun and rotated
360° around the airplane's horizontal centerline with a gun
elevation/traverse through an arc of 105°. This combination of features
provided a frontal field of fire slightly in excess of hemispherical
coverage. Three operational modes were possible; automatic, manual and
fixed. Gun laying radar was used in the automatic mode as depicted by artist
Jack Leynnwood.