In 1957 the Object 277 was developed by J.Y.Kotin's design bureau. The new tank was based on ideas from the JS-7 and the T-10. Object 277 was armed with a 130 mm M-65 Gun and coaxial 14.5 mm KPVT Machine-Gun. The gun was equipped with a "Groza" 2-plane stabilizer and a night vision system. Ammunition consisted of 26 shells for the main gun and 250 rounds for the machine-gun. The tank had a diesel engine of 1,090 h.p.
The Object 277 was equipped with an anti-nuclear defense system, a system of clearing the sights and a system for underwater river crossings. The crew consisted of four men, and the tank had good maneuverability. Two tanks were built in 1958.