This thread has convinced me at least that it is not only just possible but reasonably probable that an MC rifle could have been fired 3 times in less than 7 seconds and that JFK and JC were hit at Z233 and JFK was hit at Z313 AND the shots could be in the pattern of 1…..2.3 as per 75% witness recall.
The 1st shot as a hit at Z233 fits much closer than either the Z190 1st shot idea by Andrew Mason or the LN 1st shot which missed theory at Z-140 or earlier.
The criticisms of a Z223 1st shot seem to be:
A The shooter would not have waited until Z224 to try a 1st shot
B. SS agent Hickey moving at Z143 is indication he heard a rifle preceding Z233.
C. The shooter having scored the head shot at Z312 would not have fired a 3rd shot 2 secs after Z312.
D. The Willis girl stopped running completely by Z200 therefore a shot must have been fired before Z223.
IMO, these criticisms are not well supported and presume that the reactions of the Willis girl and SS agent Hickey were due to the sound of a rifle shot vs some other stimulus.
So Imo Dan has presented a logical and plausible 3 shot scenario which fits with witness perception of last 2 shots fired rapidly and all 3 shots in as little as 6 secs. This fits closer with Harold Norman’s 4-5 sec recollection than any other proposal offered by LNs imo. It explains lack of awareness of SS agents prior to Z207.
I've looked at every piece of evidence that has anything even remotely to do with the timing of the first shot and the overwhelming weight of evidence demonstrates, beyond any doubt, that it is the shot that passes through both JFK and JBC between frames z222 and z223. It is the only possible conclusion to come to when the totality of the evidence is taken into account.
Just to respond to the points you raise, because they are good points:
A The shooter would not have waited until Z224 to try a 1st shotThere strong evidence that the shooter had decided on the 'kill zone' long before the limo arrived in Dealey Plaza. The Sniper's Perch is an arrangement of boxes used to rest the rifle on during the shooting. We can tell from this arrangement the general direction the shooter intended to fire. As we can see from the pic below, the general direction is towards the underpass:

The second piece of evidence is the testimony of Ronald Fischer who observed something strange about the man in the SN:
"And I looked up and I watched the man for, oh, I'd say, 10 or 15 seconds. It was until the first car came around the corner of Houston and Main. And, then, when that car did come around the corner, I took my attention off of the man in the window and started watching the parade. The man held my attention for 10 or 15 seconds, because he appeared uncomfortable for one, and, secondly, he wasn't watching-uh---he didn't look like he was watching for the parade. He looked like he was looking down toward the Trinity River and the triple underpass down at the end-toward the end of Ell Street. And--uh--all the time I watched him, he never moved his head, he never-he never moved anything. Just was there transfixed."The shooter is not focused on the limo about to enter the plaza. He is staring "transfixed" in the direction of the underpass...the same direction of fire revealed by the arrangement of the Sniper's Perch. The assassin is visulaising the kill zone. Below is what the shooter was looking at:

The shooter is focused on the stretch of road just above the oak tree. This is the location where the target will have least lateral movement as it moves directly away from the shooting position. It is the easiest shot which is why, I believe, he waits until the target is in this position.
It must also be noted that the white car in the pic above is, more or less, in the same position as the limo at z222. We know this from the FBI recreation of the limo's movements:

The first shot would be taken as soon as the limo clears the oak tree meaning the first shot had to be at z222/z223
B. SS agent Hickey moving at Z143 is indication he heard a rifle preceding Z233.Personally, I don't think this is an issue. If we look at the OP we see Hickey was adamant that his reaction to the first shot was to look to his right and rear:
"I heard what seemed to me that a firecracker exploded to the right and rear. I stood partially up and turned to the rear to see if I could observe anything. "This is the precise reaction we see captured by Altgens 6 (along with that of Ready and Landis).
If we take his own words at face value then his movements around z143 have nothing to do with reacting to the sound of a shot.
C. The shooter having scored the head shot at Z312 would not have fired a 3rd shot 2 secs after Z312.The overwhelming weight of evidence forces me to conclude that the first shot was at z222/z223 and the second shot was the headshot at z312/z313. The number of witnesses describing the shot pattern - shot, pause, shot, shot - means the third shot was taken immediately after the headshot in this scenario. The weak point of this scenario is the third shot (for which the Z-film provides no evidence). The headshot is so conclusive, why would there be any need for a third shot? It doesn't make sense.
However, the majority of witnesses who were stood around the limo at the time of the shooting, the physically closest witnesses, describe either hearing a shot after the headshot - (Jack Franzen and his wife, Malcolm Summers, Emmet Hudson, Zapruder (initially), Mary Moorman, Jean Hill, Charles Brehm, June Dishong, John Templin) - or they are witnesses who only recall two shots and that the second shot was the headshot - (James Altgens, Marylin Sitzman, Bill Newman, Faye Chism, Peggy Burney, Jean Newman, Ernest Brandt).
I can only speculate as to why the shooter took a shot after the headshot...there were some witnesses who described the second and third shot as being really close together. It may have been that the shooter had decided before he took the second shot that he was going to unload whatever he had. Assuming the target was JFK's head then the first shot, even though it hit JFK, was a miss. JFK was still very much alive and time was running out for any remaining shots. After the first shot the shooter took his time to make an adjustment as this was his last realistic chance for a headshot. The decision to take the third shot had already been made but was wild and may account for the shot that hit the manhole cover.
D. The Willis girl stopped running completely by Z200 therefore a shot must have been fired before Z223.The idea that this nine year old girl was responding to the sound of a shot while a car load of SS agents failed to react is laughable. Rosemary Willis can tell us nothing about when the first shot happened.
What is interesting is that this idea that she was responding to a shot was not her own idea. One of the HSCA's photo 'experts' invented this silly notion and decades later Rosemary ran with it (following in the footsteps of her father who was quick to try and cash in on the death of the President with Phil Willis Enterprises). Rosemary not only regaled us with tales of how she reacted to the shot, she also turned and actually saw Oswald's face, smoke on the GK, a second shooter on the GK and a shooter in the storm drain.
Make of that what you will.