I'm sorry but I don't understand what the stock is for. Isn't the sniper rifle plexiglass? You're really not going to find a real world rifle stock that is a good match for the sniper rifle. The butt is shaped a bit like a machine gun--like an MG-42, for example. But it also has a pistol grip-style to the stock, just behind the trigger. And those are the least of your worries. It gets really odd when you get in front of the trigger. That's where the parts of a real gun that hold the magazine of cartridges (bullets) and the action (the parts that load bullets from the magazine into the barrel, lock it up until the gun is fired, and then extract, eject, and load another bullet are.
Actually, the more I look at it, the more it looks like a single shot rifle with a pistol grip. But not any specific rifle.
