[Legoman2179]

I have a question on how a we m4 works compared to the real thing.

In the real ar15 there's a direct impingement gas system.
The system has a gas tube that takes gas from the barrel and uses that to propel the bolt backwards into the buffer tube.

My question is, do the we m4s operate the same way with the gas tube or is the tube that runs along the top of the barrel for decoration?

Another question, the real hk416 operates with a gas piston system.
The gas pushes against the piston in the tube, which then pushes the bolt back.
Does the we 416 have a gas piston system, a direct impingement system, or niether?