The Z-film is absolutely unequivocal about the shot at z270.
It does not happen.
This is unequivocally shown in the Z-film.
If it was unequivocal you would not have to explain:
1. why we see JBC move the way he does beginning at z272. What causes him to move forward from z272 - z280 before he falls back onto Nellie? You seem to be ignoring that.
2. why we see the hand movement between z271-272. What causes the appearance of the hand and hat to change between z271 and z272? You say that change is not meaningful. Why? How is the hand going to move if the arm is pressed against the chest with the dorsal side of the wrist facing into the chest and the elbow pressed into the seat?
3. why the sunvisor moves from z271-272. What causes the sunvisor over Greer to move forward from z271-272? The wind is certainly not moving it forward. Granted it is a small movement but it is visible.
4. why the JFK hair movement occurs at z273-276. What causes JFK's hair to fly up from z273 to z276, just as Hickey described? Hickey said the second shot did not appear to hit JFK but just caused his hair to fly up.
5. why the zfilm shows Greer turning rearward around z279-z280 if nothing had just happened. And perhaps you could explain why Greer said he turned immediately after the second shot if it was unequivocally not the case.
That his wrist/hand does not move in any meaningful way demonstrates, unequivocally, a bullet has not shattered JBC's radius forcefully enough to leave fragments in the wrist and have a fragment blow through the wrist and exit near the crease of the wrist. There can be no doubt whatsoever that such a forceful blow would result in an obvious movement, it's basic physics - Newton's laws of motion, conservation of momentum etc.
If that really was the case, you will no doubt be able to explain, using physics, the following.
1. How much force does a partially spent bullet apply to the radius when it strikes the radius on an angle and fragments continue moving forward striking the windshield with enough force to crack the windshield, dent the metal frame and at least one travel 150 feet farther to strike the curb near Tague and deflect up and cut his cheek.
2. How much force is required to move a visible amount an arm that is pinned between JBC's chest and seat back?
3. What determines a visible amount of movement in the zfilm?
If you cannot show unequivocally that such movement would be visible in the zfilm, then it is not unequivocal.
I ask anyone reading this post to closely study the images below and ask themselves if it is possible, even given the most fantastical assumptions, that these images represent a bullet exploding out of JBC's chest and shattering his radius leaving fragments embedded in his wrist.
I could use the same kind of argument to "prove" that there is no SBT shot at z223 because the laws of physics do not permit the bullet, after having exploded out of JBC's chest, to shatter his radius and
not deflect away from the point of contact. The bullet would have to strike the radius and deflect leftward but the impact was on the back of the wrist on the distal side of the radius (the side nearest the ulna bone). The main difference is that you are arguing about the magnitude of the force of impact. I am saying that the direction of the force is wrong at z223. In your case, you have yet to show that the magnitude of the force would be great enough to move the wrist. In my case, it is a physical principle that is at issue: a bullet deflects away from, not toward, the point of contact.
If you would like a bit of help to get you started:
- Speed of bullet exiting chest: 400 m/sec. (original speed at impact on back: 560 m/sec or 1825 fps (muzzle speed of 2100 less 275 fps).
- Speed of bullet exiting wrist after fracturing radius: 200 m/sec.
- Momentum transferred to wrist = mΔv = .01 x 200 = 2 kg m/sec = 2 N. sec.
Therefore, a contrary force of 20 Newtons applied for 1/10th of a second will stop that momentum. A 20 N force is the weight of 2 kg or 5 pounds. I would suggest that the force applied to the arm by the pinning of the arm between the seat back and the chest is at least 5 pounds. The effect of the arm being pressed to the chest will be that the impact on the chest and wrist will cause the whole upper body to move, which is what we see from z271-278 until Nellie pulls JBC back on top of her.