The M43 is a heavy 120mm smoothbore mortar of Russian origin. The M38 is also known as the M1938 or PM-38. The M43 is a slightly updated model that was produced in much larger numbers than the M38 as it was widely exported and produced until the later stages of the Cold War.

The design is based on the French Brandt Mle 35 mortar. The M38 is a conventional smoothbore muzzle loaded mortar. Besides having longer shock absorbers and some other minor differences the M43 is similar. The system consists of four major parts: the barrel, base-plate, bipod and two wheel carriage. The fixed spread bipod allows for manual traverse and elevation. A crew of six is normally used to operate the weapon.

The M43 provides a lot of fire power with its ability to fire 12 to 15 rounds per minute to targets ranging 460 to 5.700 meters. The 120mm shells are very powerful. At the time of development the design was very modern. Judging by today's standard the range is somewhat limited and the weight is excessive.

For a heavy mortar the M43 is very mobile due to its well designed two wheel carriage. Normally it is towed or transported by a light truck, but can be hand drawn over short distances by infantry.

Russia has been the main user of the M43 mortar, although it has been replaced by the 2S11 mortar. Most Soviet allies received the M43, but due to its age more and more users are replacing it with more modern designs. However, the M43 still is one of the most common heavy mortars in the world.