M-56

The M-56 is a 105 mm towed howitzer developed in the Socialist Federal Republic of Yugoslavia, drawing on the design of the German 10.5 cm leFH 18 and the American M101. The Military Technical Institute in Belgrade produced the first prototype, designated SH-1, in 1951; it was manufactured by Crvena Zastava in Kragujevac, later Zastava Arms. A second Military Technical Institute prototype, the SH-2 of 1955, formed the basis of the serial M-56.

Serial production began in 1956 at Bratstvo in Novi Travnik rather than in Serbia. This followed a 1945 decision by the Yugoslav government to relocate armament plants from Serbia to other republics to develop their industrial bases. In 1951 the Crvena Zastava works were partially dismantled, and the entire artillery programme for calibres above 20 mm, together with some 250 specialists, was transferred from the Socialist Republic of Serbia to the new Bratstvo factory in the Socialist Republic of Bosnia and Herzegovina.

The original production version used a 28-calibre barrel with a double muzzle brake, giving a maximum range of about 13 km and a minimum engagement range of 2,000 m. Rate of fire is six rounds per minute. Elevation runs from −180 to 1,200 mils, with 462 mils of traverse on the carriage.

The Military Technical Institute subsequently developed the M-56A1, fitted with a longer 33-calibre barrel rated for at least 18,000 rounds, a strengthened breechblock, a modified recoil system capable of handling modern ammunition, and a hydro-pneumatic balancer. Maximum range rises to roughly 18 km, with a rate of fire of six to eight rounds per minute. The M-56A1 is marketed by Yugoimport, while the baseline M-56 is offered by BNT TMiH in Bosnia and Herzegovina.

The M-09 Soko is a self-propelled derivative mounting the 105 mm ordnance on a truck chassis, with TAM, FAP, Tatra, KAMAZ and Mercedes vehicles among the platforms offered. It fires in both direct and indirect modes, carries up to 60 rounds, and is fitted with an integrated fire control system. Armour protection meets STANAG 4569 Level I, and a Zastava Arms M87 12.7×108 mm machine gun is provided for self-defence. Range is 15.1 km with M02 HE ERBT projectiles and 18.4 km with M02 HE ERFB/BB. The weapon fires ammunition developed for the US M101 as well as M-56A1 rounds.

Around 1,500 M-56s of all models have been built, with over 200 exported between 1998 and 2004 according to United Nations figures. The howitzer has been widely distributed and remains in service in Europe, Asia, Africa and Latin America, including Cyprus, Greece, North Macedonia, India, Indonesia, Iran, Myanmar, Pakistan, Thailand, Nigeria, El Salvador, Guatemala, Mexico — where it equips both the Army and the Naval Infantry Corps — Peru and Venezuela.

Former operators include Serbia, Bosnia and Herzegovina, Croatia and Bangladesh. Iraq fielded the M-56 during the Iran–Iraq War and again in the Persian Gulf War, and no longer operates the type.