Hey Rudy, just wanted to share more positive feedback and say thank you. After our conversation, I purchased your 5.5” barrel, bolt, and buffer for my 9mm AR build. I assembled my upper and mated it to a complete Palmetto State lower. I have since fired all sorts of 9mm ammo and have a completely reliable setup. I read a lot of posts from folks that have trouble with their 9mm builds. I had none. Thanks again.