It's Taiga-2 model for arbitrary or free type of shooting. Sorry no idea what is the English for this kind of sport.
Design by famous E.Dragunov (Dragunov sniper rifle SVD) and I.Samoilov in 1955-56.
The other name for rifle MCV-56. In production was in 1961-69 at IZHmash plant. Taiga-2 is modification of the first Taiga.
Group at 50 meters is about 1,6 cm
Nice find. With good ammo it will show smaller group.

Geno.