152 mm M1937 (ML-20)
The ML-20 was officially classified as howitzer-gun, an artillery system which combines characteristics of a howitzer and (to lesser extent) of a gun and therefore can be used in both roles. This universality was achieved by wide range of elevation angles and by using separate loading with 13 different propellant loads.
The gun was fitted with both telescopic sight for direct fire and panoramic sight for an indirect one. For ballistic calculations and meteorological corrections a special mechanical device was developed. The device, called meteoballistic summator, consisted of a specialized slide rule and a pre-calculated table. After World War II similar devices were introduced for other types of guns.
This gun was also mounted in two Soviet tank destroyers employed during WWII. These are the SU-152 and ISU-152.
Made in the USSR
Years of production: 1937-1946
Rate of fire: 4 rounds/minute
Muzzle velocity: 655 m/s
Range: 20,500 m
Transportation speed: ≤ 40 km/h
Weight: 8070 kg