This rifle is said to have been developed in response to the Munich massacre at the 1972 Summer Olympics. The West German police units could not engage the terrorists quickly enough to prevent them from killing their hostages. H&K was then commissioned to create a high accuracy, large magazine capacity, semi-automatic rifle for police and military use.
The PSG-1 appears in Call of Duty: Black Ops in both campaign and multiplayer but not in zombies. In multiplayer it is a very powerful sniper rifle and usually preferable compared to the L96A1 due to its lower recoil and the sniper rifle, itself, being semi-automatic. It can kill in one shot from the chest up to the head while needing two shots in the stomach and down. It is unlocked when all the sniper rifles are unlocked for 2000 codpoints. In campaign, it is seen in the mission "Numbers" whereas it is found in the first and second weapon caches.