So we went out the range today and shot 150 rounds through my new rifle.
When I got home I noticed that there was a space between the receiver and the handguard; no bueno. Tightened it up nice. I didn't tighten it when I got it because I just assumed it would be fine. Guess not.
But I'm worried that maybe I should have tightened the barrel nut, too. Everything "seems" solid but now I'm kind of doubtful.