Where do you get the sniper scope in Metal Gear Solid 2 sons of liberty

There is no sniper scope in Metal Gear Solid 2: Sons of Liberty, as the weapons are not customizable. This feature would not be introduced until Metal Gear Solid 4: Guns of the Patriots. The only available attachments in Metal Gear Solid 2 are the suppressors, which cannot be removed once you have attached them to their respective weapons. There is however a PSG-1 sniper rifle that one can acquire by going to the second floor of the Strut F warehouse, as well as a PSG-1T which fires tranquilizer rounds, and can be found in the flooded B2 level of Shell 2.