Hi There, I was hoping someone can help figure out what's wrong with my AR-15. My rear sight needs to be way to the right in order for the gun to be on target at 100 yards. I don't understand why this is. I stuck a long, tight-fitting wooden dowel down the barrel in order to test if my front sight is aligned with my receiver. I'm not sure, but it looks like it is not straight. Maybe the front sight base is not aligned.... but that seems unlikely, since it is held in by two taper pins. The two pins automatically align the base as I understand it. It could be that the barrel is not indexed with the receiver. Or it could be that the detachable carry handle is not properly aligned—but the handle is tightened down nicely. Should I just send this to a gunsmith to analyze and fix it? Thanks for your responses.