The Soviet arms designers have tried to approach the bullpup layout of small arms quite a while ago. According to data available to the author, this design was first tried in the PTR (anti-tank rifles), which required a long barrel, which in case of classical layout would make the rifle uncomfortable to use. The PTR by Artillery Academy in 1941 is most likely the earliest one. However the birth date of the first Soviet bullpup can be shifted back to 1936-1937.
The question of compactness for infantry small arms was of less interest, as Soviet infantry even in case of motorized infantry, would drive around in trucks and few land-lease or captured APCs had and open top.
However, as early as first contest, which took place after the end of World War 2, on of the assault rifle prototypes – the TKB-408 by Korobov – was made as bullpup. Notably less information had survived upto present time regarding its ancestor – the 1945 Korovin assault rifle.
Ever since, the bullpup small arms was always participating in Main Artillery Department’s contests and would always lose.
The “Modern” contest, was announced in 1973 for: “compact assault rifle to arm mortar, artillery, APC personel and other kind of soldiers, who require compact rifle with high firepower”.
Read more on Russian twin-environmental bullpups, history of VAL and other firearms.