The M48A2C saw improvements for the turret implementing the Mod B turret design with larger hatches for the commander and loader. The M12 rangefinder was replaced with a full-field coincidence model along with an improved turret control system. The M13 Fire Control System (FCS) consists of the M5A2 ballistic drive and mechanical M13A3 gun data computer which integrated barrel temperature data with an M17 coincidence range finder. The rangefinder is a double image coincidence image instrument used as the ranging device of the gunner's primary direct sighting and fire control system. The gunner is provided with an M20 day periscope with a magnification of x8 and an M105D day telescopic sight with a magnification of x8 and a field of view of 7.5 degrees. Range information from the rangefinder is fed into the ballistic computer through a shaft. The ballistic computer is a mechanically driven unit that permits ammunition selection, range correction, and superelevation correction by the gunner. The ballistic drive receives the range input and, through the use of cams and gears, provides superelevation information to the superelevation actuator. The superelevation actuator adds sufficient hydraulic fluid to the elevating mechanism to correctly position the gun.