In early March 2016 North Korea test fired six of its new guided 300mm rockets from a launcher vehicles that seemed familiar to many obeservers with knowledge of such things. The North Korean 300mm rocket launcher first appeared in a late 2015 parade. The North Korean 300mm rockets appeared to have a range of over 100 kilometers. The launcher vehicle was familiar because it was later identified as a Chinese ZZ2257M5857A 6x6 truck that is manufactured for civilian and military use. This was not unusual, although it was of questionable legality.
China has come under increasing criticism for allowing its manufacturers to export such “dual use” vehicles to North Korea when it is clear that they are intended for military purposes. More disturbing is the fact that the new North Korean guided rockets were using technology that could also have been Chinese, as the Chinese introduced such a guided rocket system in 2010. The earlier Chinese WM-120 MLRS (Multiple Launch Rocket Ststem) was not only similar to the new North Korea system but also used satellite guidance (GPS). The new Chinese WM-120 has two pods, each containing four rockets, mounted on a 36 ton 8x8 truck. The 273mm rockets have a maximum range of 80 kilometers and use satellite guidance to land within 25 meters of the aiming point. Rockets can be fired within five minutes of receiving the target location. The truck contains a crane, so that it takes eight minutes to load two new rocket pods.
The WM-120 is an upgrade of the older A100 rocket system. The A100 was a reverse engineered Russian BM-30. Both use 300mm rockets and a 40 ton wheeled vehicle carrying 12 rockets and a crew of three. The BM-30 entered service in the late 1980s, and was seen as the Russian answer to the U.S. MLRS (a 27 ton tracked vehicles carrying twelve, 200 kg/660 pound, 227mm rockets). All these rockets are more accurate than earlier generations of unguided rockets. The A100 fires 250 kg (550 pound) rockets as far as 80 kilometers. When first introduced there were still no satellite guided BM-30 or A100 rockets. Russia pioneered the development of modern battlefield rockets in the late 1930s, but the U.S. introduction of the high-tech MLRS in the early 1980s made these weapons much more effective.
The U.S. took this one step further in 2008 when it stopped using unguided rockets. Now only GPS guided MLRS rockets are used, which can reach out as far as 85 kilometers. Because of the success of the GPS version of the U.S. MLRS rocket the smaller, truck mounted MLRS (HIMARS) rocket launcher system has become more popular. HIMARS carries only one six MLRS rocket container (instead of two in the original MLRS vehicle), but the 12 ton truck can fit into a C-130 transport (unlike the heavier, tracked MLRS) and is much cheaper to operate. The first HIMARS entered service in 2005, about a year after GPS guided rockets did.
The GMLRS (guided multiple launch rocket system) missile is a GPS guided 227mm rocket that entered service in 2005. It was designed to land within meters of its intended target, at any range. This is possible because it uses GPS (plus a backup inertial guidance system) to find its target. In 2008 the army tested GMLRS at max range (about 85 kilometers) and found that it worked fine. This enables one HIMARS vehicle to provide support over a frontage of 170 kilometers, or, in places like Afghanistan, where the fighting can be anywhere, an area of over 20,000 square kilometers. This is a huge footprint for a single weapon (an individual HIMARS vehicle), and fundamentally changes the way you deploy artillery in combat.