BM-21

BM-21 "Grad"
A Russian BM-21-1 on display in Saint Petersburg, in May 2009
Type	Multiple rocket launcher
Place of origin	Soviet Union
Service history
In service	1963–present
Used by	See Operators
Wars	Vietnam War Lebanese Civil War Western Sahara War Angolan Civil War Cambodian–Vietnamese War Sino-Vietnamese War Iran–Iraq War Soviet War in Afghanistan Gulf War Nagorno-Karabakh War First Chechen War 1995 Cenepa War Second Chechen War Palestinian rocket attacks on Israel Russo-Georgian War Cambodian–Thai border dispute Libyan Civil War (2011) Syrian Civil War Operation Serval War in Donbass Yemeni Civil War (2015) 2016 Armenian–Azerbaijani clashes
Production history
Designer	Splav State Research and Production Enterprise
Designed	1963
Manufacturer	Splav State Research and Production Enterprise
Produced	1963–present
Variants	See Variants
Specifications (9K51)
Weight	13.71 tonnes (30,225 lb)
Length	7.35 m (24 ft 1 in)
Barrel length	3.0 m (9 ft 10 in)
Width	2.40 m (7 ft 10 in)
Height	3.09 m (10 ft 2 in)
Crew	3
Barrels	40
Rate of fire	2 rounds/s
Muzzle velocity	690 m/s (2,264 ft/s)
Maximum firing range	20 km (new rockets 30–45 km)
Sights	PG-1M panoramic telescope
Engine	V-8 gasoline ZiL-375 180 hp (130 kW)
Suspension	6×6 wheeled
Operational range	405 km (251 mi)
Speed	75 km/h (47 mph)

The BM-21 "Grad" (Russian: БМ-21 "Град"), is a Soviet truck-mounted 122 mm multiple rocket launcher. The weapons system and the M-21OF rocket it fires were developed in the early 1960s. BM stands for boyevaya mashina (combat vehicle), and the nickname grad means "hail". The complete system with the BM-21 launch vehicle and the M-21OF rocket is designated as the M-21 field rocket system. The complete system is more commonly known as a Grad multiple rocket launcher system. In NATO countries, the system (either the complete system or the launch vehicle only) was initially known as M1964. Several other countries have copied it or developed similar systems.

The M-21 field rocket system with a BM-21 launch vehicle (122 mm multiple rocket launcher (MRL) system entered service with the Soviet Army in 1963 to replace the aging 140 mm BM-14 system). The launch vehicle consists of a Ural-375D six-by-six truck chassis fitted with a bank of 40 launch tubes arranged in a rectangular shape that can be turned away from the unprotected cab. The vehicle is powered by a water-cooled V-8 180 hp gasoline engine, has a maximum road speed of 75 km/h (47 mph), road range of up to 750 kilometers (470 mi), and can cross fords up to 1.5 m (4 ft 11 in) deep. The original vehicle together with supporting equipment (including the re-supply truck 9T254 with 60 rockets) is referred to by the GRAU index "9K51"; the launcher itself has the industrial index of "2B5". In 1976, the BM-21 was mounted on the newer Ural-4320 six-by-six army truck.

The three-member crew can emplace the system and have it ready to fire in three minutes. The crew can fire the rockets from the cab or from a trigger at the end of a 64-meter (210 ft) cable. All 40 rockets can be away in as little as 20 seconds, but can also be fired individually or in small groups in several-second intervals. A PG-1M panoramic telescope with K-1 collimator can be used for sighting. The BM-21 can be packed up and ready to move in two minutes, which can be necessary when engaged by counter-battery fire. Reloading is done manually and takes about 10 minutes.