CIV TACTICAL 90% kit works great!
I bought a tactical patrol model 90% build kit and it works wonderfully. I had no problems with this upper receiver whatsoever. Fired straight and functioned perfect.
I did a one on one build with the owner and seeing the work and time he puts into these is phenomenal. These uppers are highly superior to other uppers in the same and higher price range. The owner dimples the barrel where the gas block sits to ensure that the gas block wont move. The chambers are polished, the headspace is checked, and the receiver is blueprinted to ensure the barrel fits properly.
If you want a great mil spec ar 15 I would highly recommend CIV TACTICAL.