In my gun (G&G M4), the inner barrel is held in place by the hop-up and floats inside the outer barrel. One thing I've noticed watching videos is that when firing full auto, the BBs fly everywhere even when the gun is resting. Could this be due to the piston hitting the cylinder head, causing forward recoil and making the inner barrel wobble up and down? Could the gun benefit from a bit of tape between the inner barrel and the outer barrel or would that make the problem worse?
