Just thought I would share my experience with Palmetto barrels. Only got into building ARs a year ago. Since then I have bought 3 Palmetto 10.5 in uppers, two of which are chambered in 5.56 and one in 9mm. Of the two 5.56, one is a free floated handguard, and the other is your typical colt style a2 front sight gasblock. When I went to shoot these for the first time, the a2 gasblock gun shot fine, but the free float upper would not seat the round. Couldn’t pull the charging handle back either, it was stuck. Got home and swapped parts around, troubleshooting what was at fault. Made myself a dummy firing pin to keep everything in the BCG oriented the way it should in normal operation. Eventually I determined it was the barrel. It was somewhat successful at seating and extracting wolf steel case .223, but my brass 5.56 just kept getting stuck. Went and bought a rosco bloodline 10.5 barrel and an aero precision nickle boron BCG (PSA BCG was rounding off the leading edges of the bolt) and everything worked flawlessly after that. A few months later I saw someone on a Facebook AR group post about this same issue. Informed him of what happened to me. Another few months later a buddy of mine wanted to buy an AR, and wanted to go the PSA route. He brought it over and we went about putting his lower together. When we were finished, I wanted to make sure his barrel was good, so I stuck that dummy firing pin in and tested his barrels ability to seat 5.56. Wouldn’t you know it, his was messed up too. Informed him of what I did, he got himself a rosco and we got it on there. Perhaps I am just unlucky, however I find that hard to believe. Bad QA from palmetto in the 10.5 5.56 department.