I've built some..almost all my lowers I've built from stripped receivers, and I've built a few stripped uppers from scratch also. I've used PSA and Ballisic advantage barrels..and both have proven to be just fine. I want to try someone else's for my next build. Looking at Odin works, Faxon, Radical, or maybe Rosco. I'd really like a Kreiger, but the wait time...OMG! Anyone try any of those?