Okay experts. We are all having trouble finding parts for builds. Brownell's has been out of stripped uppers. They have a bunch of Aero Precision uppers in stock now for like $72.00 each. Aren't they made for Spike as an off brand? I know they are made for some company but I can't find where I saw the information. Next questions same old dilemma. I bought two CMMG lowers, $ 119.00 each I could have gotten S&W for $ 149.00 each. Gunsmith said they did a hardness test on the steel same quality. ???? (I built one lower already, I did use a DPMS parts kit because it was available and put a CMMG 9mm upper from CTD). Fire testing sometime this weekend. Thanks for the clarity or confusion.