Philco-Ford were involved in various military gun projects from sometime in the 1960s to well into the 1970s, e.g. they produced unsuccessful contenders for the 25mm GAU-7 and 30mm GAU-8 programmes. I am trying to find out what happened to their gun business - did it just close down, or did they sell it to another company - and if so which company, and when?
Just for your amusement, this is the result so far of my efforts to track the history of the two surviving US companies involved in the automatic cannon business:
Hughes Tool Company was involved in a variety of projects, including some radical designs such as the Lockless family. Their gun department was acquired by McDonnell Douglas in 1984, which merged with Boeing in 1997; Boeing’s ordnance business was sold to Alliant Techsystems (ATK – formerly Honeywell’s defence branch) in 2002; ATK became Orbital ATK in 2015, with the range of Bushmaster Chain Guns being the responsibility of Orbital ATK Armament Systems.
General Electric was responsible for the development of the Gatling-type multibarrel rotary cannon commencing with Project Vulcan. In 1993 it sold GE Armament Systems to Martin Marietta. After Martin’s merger with Lockheed in 1995, the cannon became the responsibility of Lockheed Martin Armament Systems, which was acquired by General Dynamics in 1997. The department responsible for the rotary guns was initially General Dynamics Armament and Technical Products; this was absorbed by General Dynamics Ordnance and Tactical Systems (GD-OTS) in 2013.