Interesting, I was reading the long thread on upper/lower receiver play and wondered what makes mine rattle. My receiver is pretty solid but the handgaurd has considerable play of about 1/4 inch.
Like the guy who sent his back and got a bullseye in the mail. I'm sure my gun shoots fine, just curious if this was normal. I will say all the AR-15's that I tried at store also seemed to rattle a little.
Sounds like your handguard is really tight. Out of curiousity does your handguard have 3 vents (swiss style) or more. Mine is the one with more, which seems most common on new Classics. I have heard the other is slightly bettre. It's odd that new Classics come with two diff versions.
I wonder if 1/4 inch rotation and rattle is worth returning/rep[lacing?