I purchased an enhanced ACR 3 days ago, and while striping it noticed that the barrel is not in line with the upper. After going to the range, it shot good groups at 50 yards but all 3-4 inches to the left of center. I think my rifle may have a machining problem on the piece that holds the barrel to the upper. As I slowly pull the barrel out I can actually align the barrel straight, but once the barrel is fully seated in the upper you can tell by looking from the front and top side of the rifle that the barrel is definitely not straight. Is anyone else having this problem? I am afraid that if I am off 3-4 inches from center at 50 yards, it will be much worse at 100...200 and on down. I am waiting to hear back from Bushmaster to see what their thought are on this.