Steve, that's contradictory. The bullet passed through JFK yet it only penetrated no more than an inch or two? 
Nope.
The bullet that *passed through* JFK hit him behind the right ear at the hairline, continued on a downslope, and exited near his Adams Apple and went on to strike JBC.
The bullet that *did not* pass through JFK was a separate bullet, which hit him several inches below the collar line and to the right of his spine.
Both bullet strikes are illustrated by the SS in the photo I linked to in my post.
Does that make it clearer ?
Thanks,
Steve