My guess it's hammer forged. Still QC should've been aware of this! Might want too find out who actually made this barrel for them. The receiver pics are between the lugs on the receiver and the chamber or elsewhere on the receiver? When you 1st chambered a round, did it close easy or needed force? Did you notice any gas toward your face/hands/body when fired? If checked on go gauge only it can have false results! Also do not use tape on the back of the go gauge for a no-go gauge use as tape compresses. If a no-go passes along with a go gauge them headspacing is correct. With the afore mentioned ammo, it was factory ammo? Twice I've had Hornady ammo that was over pressured just enough to know it was................well not entirely on Hornady's side, just a short throat that made the issue. How did the fired cases look? Post a pic or 2 of them. Did it/they extract normally or a stiff bolt lift? Remove the bolt and post pics also of the face and lug area. Not knowing which reamer was used is in question as there is so many different ones. With an unfired cartridge have the bolt removed (set aside), point the barrel (muzzle end) downward and drop in a cartridge. Then slowly tilt the barrel (muzzle end) upward and see if the cartridge slides out easy.