2) The rifle couldn't be perfectly sighted using the scope (i.e., thereby eliminating the above overshoot completely) without installing two metal shims (small metal plates), which were not present when the rifle arrived for testing, and were never found. Frazier testified that there was "a rather severe scrape" on the scope tube, and that the sight could have been bent or damaged. He was unable to determine when the defect occurred before the FBI received the rifle and scope on November 27, 1963.