The problem with opening up the gas port is that you keep increasing the pressure towards dangerous levels to try to get enough energy (the area under the time pressure curve) to cycle the action. The Army or colt came up with the xm177 (?) flash hider which streaches out the pressure but that won't work in this appication cause it make the barrel longer (against the point of the whole thing) and cause the BATF has decided that it needs to be licenced as a supressor. A fellow recently came up with a great solution. He puts a little tube about 2 inchs long and twice the diameter of the gas tube, in the middle of the gas tube. This sets up a lot of reflections in the pressure wave and streaches out the pulse.
Moral of the story is, not a trivial project, but doable with this new tube. I can't remember where I read about it. SAR?