So this is odd. My barrel isn't loose at all, nor is the barrel nut itself... However, the square barrel nut washer (#104) has a slight amount of back and forth play in it when the barrel is open. If it's locked in place it gets rid of the half millimeter or so of movement. Before I crank this down so it's tight even when open I wanted to make sure this isn't intentional and meant to compress when you lock the barrel closed. Any thoughts? I gave the barrel quite a hard turn and nothing moved.