[...]
O'meara,
Perhaps you didn't understand what I wrote.
I'll try to rephrase it for you so you can understand.
Oswald was standing and awkwardly leaning forward at the 1/3-open window for his first, sharply-downward-angled, missing-everything shot which sounded different than his other two shots because the muzzle of his Carcano was just inside the building.
Oswald ejected the spent cartridge from his Carcano while he was still standing. That ejected shell didn't bounce off the stack of boxes behind him but flew unhindered all the way down to the stack of boxes to his right.
Oswald knelt and rested his left elbow / forearm on the top box for his next two shots, during which the muzzle of his Carcano was outside the building. When he ejected those two shells from his kneeling position, they bounced off the stack of boxes behind him and ended up under the window.
The different sound of the first shot, the fact that it missed everything, and the ejection pattern of the three spent shells suggest that this is what happened.
A scientific analysis of the conscious reactions of seven witnesses (including JFK, Jackie, and Governor Connally) by Roselle and Scearce in 2020 suggests that the first shot was fired half-a-second before Zapruder resumed filming at Z-133 (after a 17-second pause), and that Oswald, therefore, took 10.2 seconds to fire all three shots in the echo chamber known as Dealey Plaza.
Understand yet?
https://d7922adf-f499-4a26-96d4-8ab2d521fa35.usrfiles.com/ugd/d7922a_e280e26982b44f2c97c6e6e27026e385.pdf