I distance myself from the Max Holland/Johann Rush theory; the only thing in common is an early first shot.  They said it hit the traffic signal support pole.  In fact, it was used for the indispensable requirement of zeroing (sighting-in) the rifle (adjusting windage & elevation) and wasn’t aimed at the limousine.  You don’t just pick up a rifle and start shooting!  Especially if it has been disassembled and reassembled.  It was purposefully fired at the Main St. curb and more than three seconds earlier than Holland/Rush, exactly where the seven frames are spliced out of the Tina Towner film by the FBI to hide her camera-jiggle reaction to that first shot.

For the complete solution, see:

The Final Truth: Solving the Mystery of the JFK Assassination
Paperback and Kindle: http://www.amazon.com/gp/product/1490350578