I bought one upper from CBC through AIM surplus when AIM was selling them. The upper wouldn't cycle. Contacted CBC and CBC told me they won't warranty it because I bought it from AIM (?). I had to go through AIM and of course AIM sent me a prepaid shipping label to be sent back to them. AIM sent the upper back to CBC and after a couple of weeks I got my upper back. Problem is the CBC upper won't shoot anything but 4 inch groups or larger. I know some of you will say that's within spec but all of my other AR's will shoot smaller groups than that. Maybe I got a lemon but after dealing with a manufacturer that won't warranty their product and I have to go through the retailer, that just leaves a bad taste in my mouth.
