S.T.A.L.K.E.R. Clear Sky ~ Eliminate the mercenaries IV

Weapon: "Groza" (Thunder) OC-14 assult rifle/grenade launcher
S.T.A.L.K.E.R.: Clear Sky
http://en.wikipedia.org/wiki/S.T.A.L.K.E.R.:_Clear_Sky
http://www.kochmedia.com/
http://cs.stalker-game.com/en/
http://stalker.deepsilver.com/index.php?lang=eng