The Object 777 is a unique project of a heavy tank. The vehicle was developed at the Chelyabinsk Kirov Plant. By 1953, the design plans were made, and the dummy vehicle was built. The prototype was to feature a cast hull and streamlined turret. The 122-mm M-62-T2 gun was to be mounted on the tank. However, development proceeded no further. The Object 777 never entered mass production nor saw service.