My new and unfired Colt M4 6920's hand guard is loose and will twist a tad when you pick up the rifle. DRIVES ME NUTS cause it's new and it doesn't have to be doing that! (unless of course it was issued to me in war when all I'd care about is how reliable it operated)

Anyway, the guy on the phone from Colt told me to send the upper to the service department with my receirpt and they will check it to see if it's "Within the Tolerances". That worried me. Because of course it's probably within war tolerances, but the point is that I want my $1,000 pretty black rifle rifle to be like the other 9 out of ten rifles that don't have loose hand rails.  I would imagine that this is probably just a matter of Colt service dept changing out the M4 hand rails with a better fitting set. I'd hate to get it back 30 days later with the same loose hand rails and a note "Within Specs" and some new scratches. Can anybody venture to guess what I'll run into when dealing with Colt with this hopefully minor problem?

I have two similar what were post ban models called the MT6400C. They have the M4 handguards and they also twist a tad bit as well.  Perhaps you can call them back and see if they will swap you handguards. They have been good with me in sending out low priced parts such as pins and screws through the years.  
 They really do want to provide you with good service, but in some cases, it might be slower than you might expect.
 To test the delta ring pressure, perhaps you have an extra set of carbine handguards to try and see if [they] twist as well.

I've read about so many people complaining about Colt's attitude to the consumer, that I wasn't sure what to expect. I suppose it be best to send the whole upper so they can do what they see fit. The next Houston gunshow is not for another 5-6 weeks for to check out replacement guards.  I might as well let Colt handle it . It'll be back quicker. Colt would probably be happy to swap it out, and the shipping would cost me less then trying to buy a Colt hanguard at the shows.

Colt's customer service has been great from my personal experience, and I've heard many compliments from others on the 1911 forum board.  If they treat their 1911 customers right, I assume they would too for their AR customers.

The delta ring on all my ARs has a slight left to right twist,its normal  even on brand new rifles.As long as the barrel nut isnt twisting left to right your fine.

Yes Model927,
The handguard doesnt "twist" as if the Delta ring were responsible. The handguard turns back and forth very loosely hitting the gas tube. This indicates that either the tabs on the front ring (at the front sight) isn't stamped out properly, or the handguard itself has notches that are too large. I believe it is the latter. I went to the Dallas gun show Saturday and checked/compared this on other Colt Rifles. Only perhaps 1 out of 5 rifles would budge a little, and perhaps 1 out of 10 or 15 would slip this badly. Though it will not cause function or accuracy problems, to me it is no different then buying an expensive SUV with a badly creeking dashboard.

Thanks guys. I am encouraged with what I hear about Colt Service from you, that I will likely have this complaint remedied by them. I can't imagine it being that difficult.

I know nothing about Colt's customer service but there is no way I would send them my upper if that is all that is wrong with it.  You can be assured that you will have some new scratches.