So I put together a new upper earlier this year, it’s a 16” fluted ballistic advantage 1:8 premium barrel, from day one it would throw the first shot lower and right of the rest of the group, usually around 1 1/2” away, after the first shot the rest of the 4 shots would be very good, always sub Moa. I have tried around 7 different loads and different bullets, some factory match ammo and some quality hand loads, always the same results. I always used the bolt release to feed 1st round from mag. I then tried shooting 5 shots all from a single load using the bolt catch each round and the group opened up quite a bit, almost 2 moa. I have also tried changing the side of the mag that the first round fed from, same problem. So on the build I faced the upper and used shim stock to tighten up the barrel fit, (as I do with every build). I used a quality free float handguard, torqued correctly, nothing is in contact with the handguard, aero adjustable gas block, I have always ran it suppressed. I have switched optics, I have changed gas tubes, I have changed bolts, I have used a different lower with a different buffer system. I have shot it with the barrel both clean and dirty, I have shot with a bipod, with a front rest, with a lead sled, all the same results. I called b.a. and they had no input at all. I have come to the conclusion that I will be best off getting a different barrel and moving on but I’m one of those guys that has to know why something isn’t working. Any ideas? I’m at a loss.