The 152mm howitzer was the backbone of the Soviet artillery at the outbreak of the war. In spite of a lower rate of fire than its 75mm counterparts, it benefited from a superior range and explosive shells that were three times more destructive than the previous ones. It is therefore perfect for pounding enemy structures or concentrations of light troops, whether they are identified or not. Much less effective against armored troops, it is a large and cumbersome gun, and therefore will be slow to move around in the battlefield.
Strategy and Tactics
With a good economy, these things can be stacked. Five or so can level most producing structures or defensive fortifications in 3 volleys. However, their range is best exploited on small or even medium maps. On larger maps, they are essentially useless unless the front line is close to the enemy.
These can prove to be extremely effective in 1939 era due to most other factions limited to light artillery.
In 1941 the Soviet Union decided to cease production of the 152 mm howitzer M1938 (M-10). One of the reasons was the disbanding of the Rifle Corps between August and September 1941 and the consequent removal of the corps artillery. Moreover, all 152 mm howitzers were excluded from divisional artillery. As a result, there was no series production of 152 mm howitzers during 1942.
However, the rifle corps were re-established in late 1942 and the previous organization of artillery at the corps level was reintroduced. As a result of the halting of 152 mm howitzer production, the Red Army corps artillery lacked a weapon more mobile than the heavy 152 mm howitzer-gun M1937 (ML-20) (typically employed by army-level and Reserve of the Main Command artillery units), but more powerful than the 122 mm howitzer M1938 (M-30).
In 1942, trying to solve the problem of lack of a suitable mobile 152 mm howitzer, the design bureau headed by F. F. Petrov started to work privately on a new howitzer, based on the carriage of the M-30 and the barrel of the M-10 (which was fitted with a muzzle brake in order to reduce the recoil and thus prevent damage to the lighter carriage). The approach allowed production to begin on the new howitzer almost immediately from the stockpile of parts for both earlier guns. Given the war situation and shortages of artillery, this solution was both elegant and expedient.
Early in 1943 Petrov notified the People's Commissar of Armaments Dmitriy Ustinov about the new project. On 13 April Ustinov informed Petrov that the State Committee of Defence had requested for five of the new guns to be sent to the testing grounds on 1 May. On May the 5th, two pieces were received for trials; two days later, on May the 7th the gun was recommended for adoption, and on the 8th of August 1943 it was officially adopted as the 152 mm howitzer M1943. One and a half months later, the first series production D-1 howitzers were delivered to the Red Army representatives.
The D-1 was employed by corps artillery and the reserve of the main command units. In 1944, the rifle corps of the Red Army had one artillery regiment each. Those regiments consisted of five batteries (totaling 20 guns), equipped with the D-1 along with various other 152 mm howitzers, 122 mm gun M1931/37 (A-19), 152 mm howitzer-gun M1937 (ML-20) or 107 mm gun M1910/30. Reserve of the Main Command included howitzer regiments (48 pieces) and heavy howitzer brigades (32 pieces). Those could be merged to form artillery divisions.
The Red Army employed D-1 howitzers from 1944 onwards, during the final stages of World War II. The D-1 was used primarily used against personnel, fortifications and key structures in the enemy rear. The anti-concrete G-530 shell was also sometimes used against armored vehicles with good results. During its service the gun earned a reputation for being reliable and accurate. The D-1 was finally withdrawn from service in the mid-seventies.
Pros & Cons
+Not only does it pack a solid punch, it is also cheaper than your average heavy artillery piece.
+It enjoys the standard long range of 1.6km rather than 1.2km
+it requires no upgrade or research and replaces no other guns.
+/-as any artillery, the accuracy depends on the distance to the target.