Optimal port size depends on the gun. It's a combination of spring strength, gas puck and plug geometry, action friction, etc. Mine would only run high brass stuff with 4x .094" ports with stock springs and the CSS or stock gas pucks, even after polishing and profiling the hammer, bolt, and carrier.
Obviously, the first thing you need to do is deburring, polishing, profiling, and break-in of the action and magazines. In addition to the hammer, bolt, and carrier, the bottom portion of the barrel that extends BEHIND THE CHAMBER can often use some deburring and rounding of the inner rear corn