Now that we have a little background posted, Let us see what the model of the sniper’s nest can tell us. Coming up are a few photos that show how it appears to me things might have transpired:
In these first two images notice that both legs are pointing west (not straddling box C). This position aligns the target area at about a 45-degree angle to the torso (much like the shooting positions shown earlier in this thread). Also, the rifle is resting low enough that no one can see it from the ground outside. And, when leaning forward a little, the intersection of Main and Houston streets can be seen. Also, Brennan, Fischer, etc can see the assassin (when he leans forward). Also, please note that I am holding a remote shutter button in my left hand instead of actually gripping the fore stock of the rifle. This is common to all the photos. If I didn’t need to press the button, I would have a better grip on the fore stock.
The next image shows the rifle raised up (quick and easy to do) and aimed at the Z161 target. Notice that the barrel of the rifle is actually touching box B (the one on the window sill). I am stretched upwards as far as I can go. And I cannot get my eye close enough to the ocular lens of the scope to be within the eye relief of 3.5” for this scope. This appears to me to be probable interference that could have caused an inadvertent shot that missed the entire limo. If the intent was to shoot after the limo cleared the oak tree interference, the assassin would have needed to get prepared by getting the rifle aimed at the target a little early and begin to track the movement of the target. It makes sense to me that around Z161 might have been a logical time to begin this preparation. And keep in mind that the assassin probably would not have been able to practice this beforehand without risking that someone would see him with a rifle aimed at the street below.
The next two images show the rifle aimed at the Z225 and Z313 targets. These are both comfortable shots that do not appear to have any interference. And I had no issues positioning my eye in the correct eye relief position. These are also the two shots that apparently hit their marks.