[soldierofvalor]

The reason for this L96 being a 650mm barrel is because it is a gas version, so the barrel can be extended back into the area usually containing the long bulky spring cylinder. As for more upgrades, I would advise you still grab a silencer and mod it to actually function; you could probably end up with a virtually silent rifle. I might get a higher end barrel but the madbulls are still nice. Another thing you could do is tap the magazine and hook up an HPA tank via air hose and 2nd stage regulator. I would double check on the moving parts that go from the trigger down to the pin hitting the gas chamber, make sure everything functions VERY smoothly and be sure to keep all those parts lubed properly to ensure the best consistency possible.

 

[soldierofvalor]

With out extensive and highly complicated modifications, a 100% internal system is impossible. If you don't want the bothers of connecting a large HPA tank(put in a pouch on your person) to your rifle, you can use a small 12cu 3000psi tank strapped on the side of your but stock attached to a macro line by and ASA that runs down to the mag and going in through either a CP Shorty Regulator(w/ a low pressure gauge) or through an elbow that is attached into the bottom of the magazine. I am not sure if this will work on an L96 but if there is room either in the butt stock, grip, or any other cavity in the stock that is large enough to house the tiny little 12cu HPA tank then you can put it in there and use the same procedure used to do it externally but drill a hole for the macro line to pop out somewhere close to the magazine so it can attach to the regulator or elbow(all that is outside the body of the gun if the internal tank works is a small segment of macro line. Maybe using a 12g cartridge connector(like one on a stock class CCI Phantom) instead of an HPA tank because CO2 is still relatively consistent in airsoft guns(especially bolt rifles, and it still works in winter), I am sure it will fit internally on a L96, and you can easily buy large quantities of 12g CO2 cartridges and don't have to worry about refills.