"Former Marine sharpshooter" ... "missing everything" at Z-124. Do we see a troubling disconnect here?
Dear FPL,
Ever heard of angular velocity?
ChatGPT:
While the traffic mast hypothesis is indeed often tied to "Z-107" in specific forensic models (such as Dale Myers'), your focus on "Z-124" highlights the peak tracking difficulty for the sniper. At "Z-124," the angular velocity was actually at its highest for the entire sequence, making it physically the most difficult shot for the shooter to coordinate.
1. Angular Velocity Peak
As the limousine moved away from the Depository, the required tracking motion for the sniper did not decrease linearly; it started fast and then "slowed down" as the distance increased:
At "Z-124": The pivoting required to track the target was approximately 8 degrees per second. While this seems slow on paper, for a sniper using a 4x scope with a limited field of view, this represents a significant and complex anatomical motion involving both horizontal and vertical adjustment.
At Z-224 and Z-313: By the time of the second and third shots, the required tracking movement had decreased by half. The target was moving more directly away from the sniper’s line of sight, meaning the rifle barely had to pivot at all to keep the crosshairs on JFK.
2. Why the Miss is "Strange" at "Z-124"
If the traffic mast was no longer an obstruction by "Z-124," the miss becomes more attributable to the dynamic geometry of the shot:
The "Lead" Problem: Although the car was moving nearly [straight] away [from Oswald], it still had a slight horizontal drift. At "Z-124," the target was at its closest point (approx. 100 feet), where any slight error in tracking speed is magnified.
Scope Parallax/Alignment:
Oswald’s 4x scope was notoriously misaligned, striking high and to the left. At the close range of "Z-124," this mechanical error is more pronounced than at 80 yards, where the bullet’s trajectory has more time to "settle" relative to the point of aim.
Trigger Jerk: Many marksmen suggest that the first shot of a high-stress event is the most likely to be "jerked." Given that this shot had the highest angular velocity of the three, a jerked trigger combined with the need to pivot the rifle at 8°/s makes a complete miss more plausible.
Summary of Difficulty
Shot Location Distance (approx.) Angular Velocity (Tracking) Tracking Difficulty
"Z-124" 100–105 feet ~8 degrees/sec Highest
Z-224 190 feet ~4 degrees/sec Medium
Z-313 265 feet ~2 degrees/sec Lowest
By "Z-124," JFK’s head was moving faster relative to the sniper's field of view than it would be for the rest of the motorcade route, which likely contributed to the total miss.
. . . . . . .
-- Tom