The PSG1 is a semi-automatic sniper rifle with a 5-round magazine. It is unlocked at level 27 in multiplayer after purchasing all the others sniper rifles. It one-shot kills in the upper-body (but not in the arms). It has an excellent balance between power, firing rate and stability.
The real PSG1 is manufactured by Heckler & Koch, West-Germany and was first designed in 1972. It fires NATO 7,62mm rounds, weights 7,2kg and has a range up to 800m. It is used by various police forces and counter-terrosim units across Europe.