Just wanted to give a short report of my new C&S upper cut from a Colt 20" bbl.  I asked for an A3 upper reciever and put a Knights RAS on along with a STW three lug coupler for my suppressor.  Here are two photos (sorry they suck image wise- I'm no photographer).

[img]www.ar15.com/members/albums/Steve%2Din%2DVA%2FImage1%2Ejpg[/img]

And with the suppressor attached:

[img]www.ar15.com/members/albums/Steve%2Din%2DVA%2FImage2%2Ejpg[/img]

The lower is my registered SBR Colt SP1 preban.  I SBR'd it about a year or two ago.  I will be testing it FA when my M16A1 Form 4 arrives (was just approved).

Shot 250 rounds through without the suppressor attached with ZERO problems.  I did, however, change out the buffer in the RRA shorty stock to an M4 Heavy Buffer. It would not extract with the standard collapsible buffer (which I should have known but forgot to check).  

Shot 25 rounds with the suppressor- again ZERO malfunctions or feed/extract problems.

The upper felt and looked awesome.  The guys at C&S were timely and polite and always available.