Simulating the JFK Assassination
For the benefit of the Warren Commission, expert riflemen from the US Army and the FBI attempted to duplicate the assassins task, using the rifle that had been discovered on the sixth floor of the Texas School Book Depository.
Even after fixing some of the guns mechanical problems, and despite firing at stationary targets from an easier vantage point, they failed to achieve the combination of accuracy and speed demanded of the lone gunman: two hits out of three, within about six seconds (see Warren Commission Hearings, vol.3, p.446 and pp.40310).
http://22november1963.org.uk/lee-harvey-oswald-marksman-sharpshooter