M60 "Starship"
Even with its problems the system had shown that it could be used by an airborne tank to destroy a main battle tank. The question of whether or not it could fill its original role as the main armament of all tanks was still open. The Army had originally started development of a low-profile turret with a short barrel for their existing M60 tanks in the 1960s, but did not place an order for delivery until 1971, when the main problems with the system had been resolved. The Shillelagh-equipped M60s entered service in 1974, but were hampered by reliability problems, and were phased out in 1980. The final revision of the M60A3 used the same gun and turret as the M60A1.
Read more about this topic: MGM-51 Shillelagh