Popping the rear take down pin, and removing the Bolt Carrier Group (BCG) and Charging Handle (CH) gives us a good look at the gas tube and M4 feedramps on both the barrel extension and the upper receiver. In this case, the gas tube is perfectly centered, and the alignment on the extension to receiver is well done. The below picture shadowing gives a little more shadow than is actually present on the right feedramp. The feedramps were smooth, despite what my picture may make it look like, and not only does it chamber rounds slowly without hanging up, but pressing in with a fingernail shows nothing out of the ordinary.