The 130 mm towed field gun M-46 () is a manually loaded, towed 130 mm artillery piece, manufactured in the Soviet Union in the 1950s. It was first observed by the west in 1954.
For many years, the M-46 was one of the longest range artillery pieces in existence, with a range of more than (unassisted) and (assisted).
Design history
The order was given in April 1946 to design a "duplex" artillery pice to replace the obsolete 122 mm gun M1931/37 (A-19), 152 mm howitzer-gun M1937 (ML-20) and other World War II era field guns, such as 122 mm Model 1931, 152 mm Model 1910/30, 152 mm Model 1935 (BR-2). The new pieces, designed by the factory No 172 (MOTZ), shared the same carriage and were given the designators M-46 (130 mm) and M-47 (152 mm). The respective GRAU designators are 52-P-482 and 52-P-547. The development phase was finished in 1950 and one year later, series production began. Many M-46s were exported.
A second "duplex" artillery system was subsequently designed by FF Petrov's design bureau at Artillery Factory No 9. This comprised a 122 mm gun and a 152 mm howitzer. The D-74 122 mm field gun was a competitor to the M-46; and while many were produced, the M-46 became the only long range gun in Soviet service until new 152 mm guns were made in the 1970s.
Description
The M-46 was developed from the M-36 130 mm naval gun used on ships and for coast defence. It is a true gun, being unable to fire much above 45° and having a long barrel and a single propelling charge. In contrast, most Western field guns of this period had a dual high and low angle fire ability, a gun-howitzer.
It has a 55 calibre barrel with a tied jaw horizontal sliding-block breech and 'pepperpot' muzzle brake. The latter is not notably efficient, but subjective reports suggest that it is quite effective in reducing muzzle flash. The hydro-pneumatic recoil system comprises a buffer below the barrel and a recuperator above the barrel. The long barrel enables a substantial propelling charge by providing more length in which to achieve 'all-burnt' and hence projectile acceleration space and thus achieve its 930 m/s muzzle velocity.
The barrel is mounted on a split-trail carriage, with deep box section trails and foam filled road wheels on the ground when firing and 50° of top traverse. The small shield protects little more than the sights, possible including from the effects of muzzle blast, and some protection from machine gun fire in anti-tank engagements. The gun has long and robust trails to provide stability when firing, a large detachable spade is fitted to the end of each when the gun is brought into action.
Non-reciprocating sights are standard Soviet pattern, designed for one-man laying. Included are a direct fire anti-tank telescope, a panoramic periscopic indirect-fire sight (a dial sight) in a reciprocating mounting, an angle of sight scale, and a range drum engraved with the range (distance) scale, coupled to a mounted elevation levelling bubble. The range drum enables the standard Soviet technique of semi-direct fire when the piece is laid visually on the target and the range set on the range drum. An APN-3 was later provided for direct fire at night in place of the day telescope.
For travel, the gun is towed via a two-wheeled limber fitted to the end of the closed trails, with the spades removed and carried on each trail. Simple jacks on the trails just behind the main wheels are used to lift and support the closed trails so that the limber can be connected. The barrel and recuperator are pulled back between the closed trails and locked in a travelling position. There is a large bicycle chain arrangement on the right trail for this, and a compressed air cylinder, charged by the gun firing, is used to bring the barrel forward when the gun is brought back into action. It takes about four minutes to bring the gun into action, the normal detachment is eight strong.
Propelling charges are in metal cartridge cases and loaded separately from the projectile. Projectiles originally included HE fragmentation, Armour Piercing solid shot, smoke, illuminating and chemical. HE shells weigh ~. Illuminating shells have a substantially lower muzzle velocity. APHE and extended range shells were introduced later. Maximum rate of fire is probably 6-7 rounds/minute, and about 70 rounds/hour. The standard Soviet unit of fire was 80 rounds.