Originally Posted by Killbox
i should have specified. its just a regular JG metal front RIS system. dmy bad.
The RIS is connected to the upper reciever, I forget the names of the parts involved but it doesn't matter.
The gas block (on a standard rifle, it's one with the triangular front sight) serves the purpose of re-directing gas to the BCG (Bolt Carrier group) due to the fact that a standard AR-15 system is a Direct Impingent system. That is, it's a type of gas operation for a firearm that directs gas from a fired cartridge directly to the bolt carrier or slide assembly to cycle the action. This does away with the need for a separate gas cylinder, piston, and operating rod assembly. The high-pressure gas acts directly upon the bolt and carrier and has the effects of saving weight, lowering costs, and reducing the mass of the operating parts.
The main disadvantage of this system is an increase of fouling in the breech.
None of this has any effect on an airsoft rifle however, it may just give you a better understanding of why the gas block is there, as it's NOT there to keep your RIS in place.