Someone make be a believer in a small port gas port (less wear and tear) and a large port that will reliably shoot anything. Leads me back to why BCM only sells the A5 kit with the 0 buffer. Why expose yourself to the possibility of softer ammunition not working at the expense of longevity or recoil impulse?? While derailing the thread I want to ask one last question.... Why do you think a hammer forged barrel is better than one that isn't if both are chrome lined? In either when the chrome is gone both are worn out.