In 1940, the Red Army adopted the 7.62mm SVT-40 semi-automatic sniper rifle with a PU optical sight (7,62-мм снайперская винтовка СВТ-40 c оптическим прицелом ПУ) as their second model of standard sniper rifle. Due to several problems, including accuracy issues and muzzle flash, as well as being complex and slow to manufacture, production ceased in October 1941, and work began on developing the PU version of the Mosin–Nagant.[1]