Towed howitzer D-20 Type Towed howitzer Place of origin Soviet Union Service history Used by Soviet Union and numerous others Wars Vietnam War Six-Day War Yom Kippur War Soviet–Afghan War Iran–Iraq War Lebanese Civil War First Nagorno-Karabakh War Syrian Civil War Russo-Ukrainian War 2020 Nagorno-Karabakh conflict and numerous other conflicts Production history Designer Petrov Artillery Design Bureau Designed Circa 1947 Manufacturer Artillery Plant Number 9, Yekaterinburg Specifications Mass 5,700 kg (12,566 lbs) Length 8.69 m (28 ft 6 in) Barrel length 3.962 m (13 ft 0 in) L/26 Width 2.35 m (7 ft 9 in) Height 1.93 m (6 ft 4 in) Crew 8 Shell 152 x 547.5mm .R Separate loading charge and projectile[1] Caliber 152.4 mm (6.0 in) Breech Vertical semi-automatic sliding-wedge Recoil hydraulic buffer and hydro-pneumatic recuperator Carriage Split trail Elevation -5° to 45° Traverse 58° Rate of fire Burst: 5–6 rpm Sustained: 1 rpm Muzzle velocity 650 m/s (2,132 ft/s) (typical) Effective firing range 17.4 km (11 mi) Maximum firing range 24 km (15 mi) (rocket assisted projectile) Sights PG1M indirect sight and OP4M direct fire sight