Is this a hostel ? if it is which one and where ? !<| sep |> What does manufacturing have to do with it ? The purpose of most PhDs and science is not to develop products to be made in an American factory . It ' s hard to get a tenuretrack research job , but unemployment for PhDs in the US is very , very low . I agree that it shouldn ' t be so hard to be a professor or the equivalent at a government research center , but the situation for us is very , very different from Berlin in the 70 s or whatever . <| sep |> Almost every company has different finish machining for their uppers to my understanding so they all vary in fitment . It would be great to have a consolidated post of what all the gaps look like close up on rar 10 . I have no problems with the rifle , the gap is a bit large but doesn ' t interfere with functionality in my experience thus far . Eventually I may get another for a novel caliber , but currently my state doesn ' t allow centerfire necked rifle cartridges for deer . sanding has been performed . This is how the basic gap looks , as it did in my old post without a light behind it . The BCG , CH , and bufferspring have been removed in the above photo . I can edit in links later if needed of my initial post . This photo is also not sanded , I only put a lot of downward force towards grip on the stock to see what sort of flex the lower has . There isn ' t much , but it could mimic the end results after sanding the vertical receiver facing side of the tower . The lower curvature part of the gap doesn ' t really change . The slight angle in the gap at the top of the buffer tube tower does disappear . I still may sand it to see since it doesn ' t void the warranty , but don ' t have moon high hopes of making it flush . Regards , Dr . WW