To tell the truth, when looking at the fatal headshot, it’s a good idea to start from the beginning.
Now, it is completely true that a jacketed, military rifle bullet will punch a small hole in whatever it hits and blow a large hole out the other side. However, many bullet fragments were found in Kennedy’s brain at the autopsy, and jacketed bullets do not fragment so extensively. Therefore, the bullet that hit Kennedy in the head was an unjacketed bullet: a soft one. Possibly even a frangible one.
Now that we know that the bullet was not jacketed, let’s just assume, for the sake of theory, that Kennedy was shot from the knoll. The official version asserts that Kennedy was killed by a high-powered rifle shot. Also, if Kennedy was hit from the knoll, from the location that most witnesses place the shooter, he would have to be hit from an angle to the right-front. The testimony of the Dallas doctors confirms this; they say that he had a open flap of skull and scalp at his right temple, and a large, gaping hole in the lower back of his head, on the right-hand side.
This means the the bullet entered his temple, went through his head from front-to-back, and exited the right-back of his head; it’s path was just an inch or so beneath the skull. Now, I’m not an expert, but I find it hard to believe that a high-powered–the keyword is high-powered–rifle shot with a soft, unjacketed bullet could hit a person’s head at an angle like that, traverse the brain at a depth just barely under the skull, and NOT crack the skull open, rip the scalp open, and explosively blow brain matter out of the resulting gap, all BEFORE it blows a large exit hole in the back. It makes complete sense.
The size question about exit vs. entrance wounds don’t apply to human skulls as neatly as it does to a human torso or limb. A pistol shot would work fine, but a rifle shot is too high-speed and high-power to not shatter the skull on impact, although it certainly would not punch a large hole on impact. There was no huge hole in JFK’s temple, only a large, ragged flap of skull and scalp.
Furthermore, if a large hole was punched, the blood and brains would fly straight out the hole, right into the face of Agent Kellerman, who was sitting in the front passenger seat. However, a look at the Zapruder film shows that brains blow outwards, all over, and towards the back. A large ring made made up of pieces of brain matter and/or skull fragments flies up above Kennedy’s head and pops backwards, *backwards*. A look at the Muchmore film, taken from the side of the street opposite Zapruder, shows a twisting spray of the same chunks of brain and skull shooting upwards and back towards the rear of the limousine. Both films are further supported by Bobby Hargis, the motorcyclist riding at the limo’s left rear taillight, who was hit in the face with a sheet of blood, brains, and bone issuing from Kennedy’s head.
Finally, a huge number of doctors at Parkland hospital, where Kennedy was taken minutes after the shooting, said that there was a large, gaping exit wound at the back of Kennedy’s head. All of them said that the assertion that there was a wound of entry in back and a wound of exit in front was totally wrong. Nurses and doctors give detailed descriptions of what they did to treat the back-of-the-head wound, they are not uncertain about it, and could not have mistaken a wound like that. Oh, last point: remember high school physics? Remember toddler-level instinct that lets you judge what a person’s movements mean? And common sense? Remember the properties of the universe that you take for granted every minute of every day? Kennedy was hit, lifted up and thrown, his head moving at 100 feet per second, back and to the left. Back and to the left. It’s really just that simple.